diff --git a/MODEL_COMPILATION_ON_BUILDTIME_CONTRACT.md b/MODEL_COMPILATION_ON_BUILDTIME_CONTRACT.md
index 2db9a43..a720dd7 100644
--- a/MODEL_COMPILATION_ON_BUILDTIME_CONTRACT.md
+++ b/MODEL_COMPILATION_ON_BUILDTIME_CONTRACT.md
@@ -423,7 +423,7 @@ Minimum messages:
 - `Preparing model compiler...`
 - `Preparing model compilation workspace...`
 - `Compiling model 12/324: part/belt/pfa0_belt018.mdl`
-- `Reusing compiled model: vfxs/headaccessory/hfx_bandana.mdl`
+- `Reusing compiled model: vfxs/head_accessories/hfx_bandana.mdl`
 - `Skipping binary model source: creatures/foo.mdl`
 - `FAILED model compile: placeables/broken_model.mdl`
 
diff --git a/internal/pipeline/pipeline_test.go b/internal/pipeline/pipeline_test.go
index ba32dbe..d3ae836 100644
--- a/internal/pipeline/pipeline_test.go
+++ b/internal/pipeline/pipeline_test.go
@@ -2178,10 +2178,10 @@ func TestPlanHAKsWritesManifestWithoutArchives(t *testing.T) {
 func TestBuildHAKsWritesConfiguredHeadVisualeffectsAutogenManifest(t *testing.T) {
 	root := t.TempDir()
 	mustMkdir(t, filepath.Join(root, "src"))
-	mustMkdir(t, filepath.Join(root, "assets", "vfxs", "chestaccessory"))
-	mustMkdir(t, filepath.Join(root, "assets", "vfxs", "headaccessory"))
-	mustMkdir(t, filepath.Join(root, "assets", "vfxs", "headdecoration"))
-	mustMkdir(t, filepath.Join(root, "assets", "vfxs", "headfeature", "hair"))
+	mustMkdir(t, filepath.Join(root, "assets", "vfxs", "chest_accessories"))
+	mustMkdir(t, filepath.Join(root, "assets", "vfxs", "head_accessories"))
+	mustMkdir(t, filepath.Join(root, "assets", "vfxs", "head_decorations"))
+	mustMkdir(t, filepath.Join(root, "assets", "vfxs", "head_features", "hair"))
 	mustMkdir(t, filepath.Join(root, "build"))
 
 	mustWriteFile(t, filepath.Join(root, "nwn-tool.json"), `{
@@ -2200,7 +2200,7 @@ func TestBuildHAKsWritesConfiguredHeadVisualeffectsAutogenManifest(t *testing.T)
       {
         "id": "head_visualeffects",
         "root": "vfxs",
-        "include": ["chestaccessory/**/*.mdl", "headaccessory/**/*.mdl", "headdecoration/**/*.mdl", "headfeature/**/*.mdl"],
+        "include": ["chest_accessories/**/*.mdl", "head_accessories/**/*.mdl", "head_decorations/**/*.mdl", "head_features/**/*.mdl"],
         "derive": {
           "kind": "model_stem",
           "group_from": "first_path_segment"
@@ -2212,8 +2212,8 @@ func TestBuildHAKsWritesConfiguredHeadVisualeffectsAutogenManifest(t *testing.T)
         },
         "head_visualeffects": {
           "groups": {
-            "headaccessory": {
-              "prefix": "headaccessory",
+            "head_accessories": {
+              "prefix": "head_accessories",
               "model_columns": ["Imp_HeadCon_Node", "Imp_Root_H_Node"]
             }
           }
@@ -2233,10 +2233,10 @@ func TestBuildHAKsWritesConfiguredHeadVisualeffectsAutogenManifest(t *testing.T)
 }
 `)
 
-	mustWriteFile(t, filepath.Join(root, "assets", "vfxs", "chestaccessory", "tfx_sash.mdl"), "sash")
-	mustWriteFile(t, filepath.Join(root, "assets", "vfxs", "headaccessory", "hfx_bandana.mdl"), "bandana")
-	mustWriteFile(t, filepath.Join(root, "assets", "vfxs", "headdecoration", "hfx_laurel.mdl"), "laurel")
-	mustWriteFile(t, filepath.Join(root, "assets", "vfxs", "headfeature", "hair", "hfx_hair_bangs.mdl"), "hair")
+	mustWriteFile(t, filepath.Join(root, "assets", "vfxs", "chest_accessories", "tfx_sash.mdl"), "sash")
+	mustWriteFile(t, filepath.Join(root, "assets", "vfxs", "head_accessories", "hfx_bandana.mdl"), "bandana")
+	mustWriteFile(t, filepath.Join(root, "assets", "vfxs", "head_decorations", "hfx_laurel.mdl"), "laurel")
+	mustWriteFile(t, filepath.Join(root, "assets", "vfxs", "head_features", "hair", "hfx_hair_bangs.mdl"), "hair")
 
 	p, err := project.Load(root)
 	if err != nil {
@@ -2267,16 +2267,16 @@ func TestBuildHAKsWritesConfiguredHeadVisualeffectsAutogenManifest(t *testing.T)
 	text := string(headRaw)
 	for _, want := range []string{
 		`"id": "head_visualeffects"`,
-		`"group": "chestaccessory"`,
+		`"group": "chest_accessories"`,
 		`"model_stem": "tfx_sash"`,
-		`"group": "headaccessory"`,
+		`"group": "head_accessories"`,
 		`"model_stem": "hfx_bandana"`,
 		`"head_visualeffects": {`,
 		`"model_columns": [`,
 		`"Imp_Root_H_Node"`,
-		`"group": "headdecoration"`,
+		`"group": "head_decorations"`,
 		`"model_stem": "hfx_laurel"`,
-		`"group": "headfeature"`,
+		`"group": "head_features"`,
 		`"model_stem": "hfx_hair_bangs"`,
 	} {
 		if !strings.Contains(text, want) {
@@ -2288,7 +2288,7 @@ func TestBuildHAKsWritesConfiguredHeadVisualeffectsAutogenManifest(t *testing.T)
 func TestBuildHAKsWritesFolderCategoryInHeadVisualeffectsAutogenManifest(t *testing.T) {
 	root := t.TempDir()
 	mustMkdir(t, filepath.Join(root, "src"))
-	mustMkdir(t, filepath.Join(root, "assets", "vfxs", "headfeature", "sinfar", "ears_plt"))
+	mustMkdir(t, filepath.Join(root, "assets", "vfxs", "head_features", "sinfar", "ears_plt"))
 	mustMkdir(t, filepath.Join(root, "build"))
 
 	mustWriteFile(t, filepath.Join(root, "nwn-tool.json"), `{
@@ -2307,7 +2307,7 @@ func TestBuildHAKsWritesFolderCategoryInHeadVisualeffectsAutogenManifest(t *test
       {
         "id": "head_visualeffects",
         "root": "vfxs",
-        "include": ["headfeature/**/*.mdl"],
+        "include": ["head_features/**/*.mdl"],
         "derive": {
           "kind": "model_stem",
           "group_from": "first_path_segment"
@@ -2319,7 +2319,7 @@ func TestBuildHAKsWritesFolderCategoryInHeadVisualeffectsAutogenManifest(t *test
         },
         "head_visualeffects": {
           "groups": {
-            "headfeature": {
+            "head_features": {
               "model_columns": ["Imp_HeadCon_Node", "Imp_Root_H_Node"]
             }
           },
@@ -2346,7 +2346,7 @@ func TestBuildHAKsWritesFolderCategoryInHeadVisualeffectsAutogenManifest(t *test
 }
 `)
 
-	mustWriteFile(t, filepath.Join(root, "assets", "vfxs", "headfeature", "sinfar", "ears_plt", "hfx_Ear_EL_L.mdl"), "ear")
+	mustWriteFile(t, filepath.Join(root, "assets", "vfxs", "head_features", "sinfar", "ears_plt", "hfx_Ear_EL_L.mdl"), "ear")
 
 	p, err := project.Load(root)
 	if err != nil {
@@ -2368,11 +2368,11 @@ func TestBuildHAKsWritesFolderCategoryInHeadVisualeffectsAutogenManifest(t *test
 	}
 	text := string(headRaw)
 	for _, want := range []string{
-		`"group": "headfeature"`,
+		`"group": "head_features"`,
 		`"subgroup": "sinfar/ears_plt"`,
 		`"category": "ears_plt"`,
 		`"model_stem": "hfx_Ear_EL_L"`,
-		`"source": "headfeature/sinfar/ears_plt/hfx_Ear_EL_L.mdl"`,
+		`"source": "head_features/sinfar/ears_plt/hfx_Ear_EL_L.mdl"`,
 		`"group_token_source": "folder_name"`,
 		`"category_from": "immediate_parent"`,
 	} {
diff --git a/internal/project/project_test.go b/internal/project/project_test.go
index 288fec2..f0365fb 100644
--- a/internal/project/project_test.go
+++ b/internal/project/project_test.go
@@ -1332,7 +1332,7 @@ func TestValidateLayoutRejectsInvalidAutogenConsumerConfig(t *testing.T) {
 						Dataset:  "visualeffects",
 						Mode:     "unsupported",
 						Root:     "vfxs",
-						Include:  []string{"headaccessory/**/*.mdl"},
+						Include:  []string{"head_accessories/**/*.mdl"},
 						Derive:   AutogenDeriveConfig{Kind: "model_stem", GroupFrom: "first_path_segment"},
 						Manifest: AutogenManifestConfig{
 							ReleaseTag: "head-vfx-manifest-current",
@@ -1434,7 +1434,7 @@ func TestValidateLayoutRejectsInvalidHeadVisualeffectsNamingConfig(t *testing.T)
 						Dataset:  "visualeffects",
 						Mode:     "head_visualeffects",
 						Root:     "vfxs",
-						Include:  []string{"headfeature/**/*.mdl"},
+						Include:  []string{"head_features/**/*.mdl"},
 						Derive:   AutogenDeriveConfig{Kind: "model_stem", GroupFrom: "first_path_segment"},
 						Manifest: AutogenManifestConfig{
 							ReleaseTag: "head-vfx-manifest-current",
@@ -1443,7 +1443,7 @@ func TestValidateLayoutRejectsInvalidHeadVisualeffectsNamingConfig(t *testing.T)
 						},
 						HeadVisualeffects: HeadVisualeffectsConfig{
 							Groups: map[string]HeadVisualeffectGroupConfig{
-								"headfeature": {},
+								"head_features": {},
 							},
 							GroupTokenSource: "unsupported",
 							CategoryFrom:     "unsupported",
@@ -1488,19 +1488,19 @@ autogen:
       mode: head_visualeffects
       root: vfxs
       include:
-        - headfeature/**/*.mdl
+        - head_features/**/*.mdl
       derive:
         kind: model_stem
         group_from: first_path_segment
       head_visualeffects:
         groups:
-          headfeature:
+          head_features:
             model_columns:
               - Imp_HeadCon_Node
         group_token_source: folder_name
         category_from: immediate_parent
         legacy_groups:
-          head_features: headfeature
+          head_features: head_features
         legacy_key_format: "{dataset}:{group}_{stem}"
 `)
 
@@ -1557,7 +1557,7 @@ func TestValidateLayoutAcceptsGeneratedTopData2DAConfig(t *testing.T) {
 							ID:      "cachedmodels",
 							Mode:    "cachedmodels_rows",
 							Root:    "vfxs",
-							Include: []string{"headaccessory/**/*.mdl", "headfeature/**/*.mdl"},
+							Include: []string{"head_accessories/**/*.mdl", "head_features/**/*.mdl"},
 							Derive:  AutogenDeriveConfig{Kind: "model_stem", GroupFrom: "first_path_segment"},
 						},
 					},
diff --git a/internal/topdata/autogen.go b/internal/topdata/autogen.go
index fd7094e..1c3cb99 100644
--- a/internal/topdata/autogen.go
+++ b/internal/topdata/autogen.go
@@ -850,10 +850,10 @@ func applyHeadVisualeffectsConfig(policy *headVisualeffectsPolicy, cfg project.H
 func defaultHeadVisualeffectsPolicy() headVisualeffectsPolicy {
 	return headVisualeffectsPolicy{
 		Groups: map[string]headVisualeffectsGroupPolicy{
-			"chestaccessory": {},
-			"headaccessory":  {},
-			"headdecoration": {},
-			"headfeature":    {},
+			"chest_accessories": {},
+			"head_accessories":  {},
+			"head_decorations": {},
+			"head_features":    {},
 		},
 		GroupTokenSource:   "folder_name",
 		CategoryFrom:       "immediate_parent",
diff --git a/internal/topdata/topdata_test.go b/internal/topdata/topdata_test.go
index a71b9bb..8905fc9 100644
--- a/internal/topdata/topdata_test.go
+++ b/internal/topdata/topdata_test.go
@@ -6858,7 +6858,7 @@ func TestNormalizeProjectImportsLegacyVisualeffects(t *testing.T) {
 }`+"\n")
 	writeFile(t, filepath.Join(root, "reference", "data", "visualeffects", "lock.json"), `{
   "visualeffects:chatbubble": 10100,
-  "visualeffects:headaccessory_antlers_l": 10101,
+  "visualeffects:head_accessories_antlers_l": 10101,
   "visualeffects:vcm_hitmasscrit": 10125,
   "visualeffects:com_hitnegative": 288,
   "visualeffects:fnf_blinddeaf": 18
@@ -6919,8 +6919,8 @@ func TestNormalizeProjectImportsLegacyVisualeffects(t *testing.T) {
 }`+"\n")
 	writeFile(t, filepath.Join(root, "reference", "data", "visualeffects", "modules", "accessories", "add_eos.json"), `{
   "entries": {
-    "visualeffects:headaccessory_antlers_l": {
-      "Label": "headaccessory_ANTLERS_L",
+    "visualeffects:head_accessories_antlers_l": {
+      "Label": "head_accessories_ANTLERS_L",
       "Type_FD": "D",
       "OrientWithGround": "0",
       "Imp_HeadCon_Node": "hfx_antlers_l",
@@ -6986,7 +6986,7 @@ func TestNormalizeProjectImportsLegacyVisualeffects(t *testing.T) {
 		t.Fatalf("read visualeffects lock: %v", err)
 	}
 	lockText := string(lockRaw)
-	if !strings.Contains(lockText, `"visualeffects:chatbubble": 10100`) || !strings.Contains(lockText, `"visualeffects:headaccessory_antlers_l": 10101`) {
+	if !strings.Contains(lockText, `"visualeffects:chatbubble": 10100`) || !strings.Contains(lockText, `"visualeffects:head_accessories_antlers_l": 10101`) {
 		t.Fatalf("expected imported visualeffects lock IDs, got:\n%s", lockText)
 	}
 }
@@ -7005,7 +7005,7 @@ func TestBuildSupportsCanonicalVisualeffects(t *testing.T) {
 }`+"\n")
 	writeFile(t, filepath.Join(root, "topdata", "data", "visualeffects", "lock.json"), `{
   "visualeffects:chatbubble": 10100,
-  "visualeffects:headaccessory_antlers_l": 10101,
+  "visualeffects:head_accessories_antlers_l": 10101,
   "visualeffects:vcm_hitmasscrit": 10125,
   "visualeffects:com_hitnegative": 288,
   "visualeffects:fnf_blinddeaf": 18
@@ -7066,8 +7066,8 @@ func TestBuildSupportsCanonicalVisualeffects(t *testing.T) {
 }`+"\n")
 	writeFile(t, filepath.Join(root, "topdata", "data", "visualeffects", "modules", "accessories", "add_eos.json"), `{
   "entries": {
-    "visualeffects:headaccessory_antlers_l": {
-      "Label": "headaccessory_ANTLERS_L",
+    "visualeffects:head_accessories_antlers_l": {
+      "Label": "head_accessories_ANTLERS_L",
       "Type_FD": "D",
       "OrientWithGround": "0",
       "Imp_HeadCon_Node": "hfx_antlers_l",
@@ -7113,7 +7113,7 @@ func TestBuildSupportsCanonicalVisualeffects(t *testing.T) {
 		"18\tVFX_FNF_BLINDDEAF\tF\t0",
 		"288\tVFX_COM_HIT_NEGATIVE\tF\t0",
 		"10100\tVFX_DUR_CHAT_BUBBLE\tD\t0",
-		"10101\theadaccessory_ANTLERS_L\tD\t0",
+		"10101\thead_accessories_ANTLERS_L\tD\t0",
 		"10125\tVFX_COM_HIT_MASSIVE_CRITICALS\tF\t0",
 		"scm_hitsmite",
 		"vff_explblind_l",
@@ -7147,7 +7147,7 @@ with open(os.path.join(out, "visualeffects.2da"), "w", encoding="utf-8") as f:
     f.write("18\tVFX_FNF_BLINDDEAF\tF\t0\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\tvff_explblind_l\t0\n")
     f.write("288\tVFX_COM_HIT_NEGATIVE\tF\t0\t****\t****\t****\t****\t****\t****\tscm_hitsmite\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t0\n")
     f.write("10100\tVFX_DUR_CHAT_BUBBLE\tD\t0\tvdr_chatbubble\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t0\n")
-    f.write("10101\theadaccessory_ANTLERS_L\tD\t0\thfx_antlers_l\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t0\n")
+    f.write("10101\thead_accessories_ANTLERS_L\tD\t0\thfx_antlers_l\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t0\n")
     f.write("10125\tVFX_COM_HIT_MASSIVE_CRITICALS\tF\t0\t****\tvcm_hitmasscrit\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t****\t0\n")
 with open(os.path.join(tlk, "sow_tlk.tlk"), "wb") as f:
     f.write(b"TLK")
@@ -7163,7 +7163,7 @@ with open(os.path.join(tlk, "sow_tlk.tlk"), "wb") as f:
 }`+"\n")
 		writeFile(t, filepath.Join(root, target, "data", "visualeffects", "lock.json"), `{
   "visualeffects:chatbubble": 10100,
-  "visualeffects:headaccessory_antlers_l": 10101,
+  "visualeffects:head_accessories_antlers_l": 10101,
   "visualeffects:vcm_hitmasscrit": 10125,
   "visualeffects:com_hitnegative": 288,
   "visualeffects:fnf_blinddeaf": 18
@@ -7224,8 +7224,8 @@ with open(os.path.join(tlk, "sow_tlk.tlk"), "wb") as f:
 }`+"\n")
 		writeFile(t, filepath.Join(root, target, "data", "visualeffects", "modules", "accessories", "add_eos.json"), `{
   "entries": {
-    "visualeffects:headaccessory_antlers_l": {
-      "Label": "headaccessory_ANTLERS_L",
+    "visualeffects:head_accessories_antlers_l": {
+      "Label": "head_accessories_ANTLERS_L",
       "Type_FD": "D",
       "OrientWithGround": "0",
       "Imp_HeadCon_Node": "hfx_antlers_l",
@@ -7328,12 +7328,12 @@ func TestApplyAutogenConsumersAugmentsPartsFromLocalOverride(t *testing.T) {
 func TestApplyAutogenConsumersAugmentsHeadVisualeffectsFromLocalOverride(t *testing.T) {
 	root := testProjectRoot(t)
 	overrideRoot := filepath.Join(root, "autogen-assets")
-	mkdirAll(t, filepath.Join(overrideRoot, "vfxs", "headaccessory", "hat"))
-	mkdirAll(t, filepath.Join(overrideRoot, "vfxs", "headdecoration", "laurel"))
-	mkdirAll(t, filepath.Join(overrideRoot, "vfxs", "headfeature", "hair"))
-	writeFile(t, filepath.Join(overrideRoot, "vfxs", "headaccessory", "hat", "hfx_bandana.mdl"), "mdl\n")
-	writeFile(t, filepath.Join(overrideRoot, "vfxs", "headdecoration", "laurel", "hfx_laurel.mdl"), "mdl\n")
-	writeFile(t, filepath.Join(overrideRoot, "vfxs", "headfeature", "hair", "hfx_hair_bangs.mdl"), "mdl\n")
+	mkdirAll(t, filepath.Join(overrideRoot, "vfxs", "head_accessories", "hat"))
+	mkdirAll(t, filepath.Join(overrideRoot, "vfxs", "head_decorations", "laurel"))
+	mkdirAll(t, filepath.Join(overrideRoot, "vfxs", "head_features", "hair"))
+	writeFile(t, filepath.Join(overrideRoot, "vfxs", "head_accessories", "hat", "hfx_bandana.mdl"), "mdl\n")
+	writeFile(t, filepath.Join(overrideRoot, "vfxs", "head_decorations", "laurel", "hfx_laurel.mdl"), "mdl\n")
+	writeFile(t, filepath.Join(overrideRoot, "vfxs", "head_features", "hair", "hfx_hair_bangs.mdl"), "mdl\n")
 
 	p := testProject(root)
 	p.Config.Autogen.Consumers = []project.AutogenConsumerConfig{
@@ -7343,7 +7343,7 @@ func TestApplyAutogenConsumersAugmentsHeadVisualeffectsFromLocalOverride(t *test
 			Dataset:           "visualeffects",
 			Mode:              "head_visualeffects",
 			Root:              "vfxs",
-			Include:           []string{"headaccessory/**/*.mdl", "headdecoration/**/*.mdl", "headfeature/**/*.mdl"},
+			Include:           []string{"head_accessories/**/*.mdl", "head_decorations/**/*.mdl", "head_features/**/*.mdl"},
 			Derive:            project.AutogenDeriveConfig{Kind: "model_stem", GroupFrom: "first_path_segment"},
 			Manifest:          project.AutogenManifestConfig{ReleaseTag: "head-vfx-manifest-current", AssetName: "sow-head-vfx-manifest.json", CacheName: "sow-head-vfx-manifest.json"},
 			LocalOverrideRoot: "autogen-assets",
@@ -7374,37 +7374,37 @@ func TestApplyAutogenConsumersAugmentsHeadVisualeffectsFromLocalOverride(t *test
 		rowByKey[row["key"].(string)] = row
 	}
 
-	bandana := rowByKey["visualeffects:headaccessory/hat/bandana"]
+	bandana := rowByKey["visualeffects:head_accessories/hat/bandana"]
 	if bandana == nil {
 		t.Fatalf("expected head accessory row, got %#v", got[0].Rows)
 	}
-	if bandana["Label"] != "headaccessory/hat/bandana" || bandana["Imp_HeadCon_Node"] != "hfx_bandana" || bandana["OrientWithObject"] != "1" {
+	if bandana["Label"] != "head_accessories/hat/bandana" || bandana["Imp_HeadCon_Node"] != "hfx_bandana" || bandana["OrientWithObject"] != "1" {
 		t.Fatalf("unexpected head accessory defaults: %#v", bandana)
 	}
 
-	laurel := rowByKey["visualeffects:headdecoration/laurel/laurel"]
+	laurel := rowByKey["visualeffects:head_decorations/laurel/laurel"]
 	if laurel == nil {
 		t.Fatalf("expected head decoration row, got %#v", got[0].Rows)
 	}
-	if laurel["Label"] != "headdecoration/laurel/laurel" || laurel["Imp_HeadCon_Node"] != "hfx_laurel" || laurel["Type_FD"] != "D" {
+	if laurel["Label"] != "head_decorations/laurel/laurel" || laurel["Imp_HeadCon_Node"] != "hfx_laurel" || laurel["Type_FD"] != "D" {
 		t.Fatalf("unexpected head decoration defaults: %#v", laurel)
 	}
 
-	hair := rowByKey["visualeffects:headfeature/hair/hair_bangs"]
+	hair := rowByKey["visualeffects:head_features/hair/hair_bangs"]
 	if hair == nil {
 		t.Fatalf("expected head feature row, got %#v", got[0].Rows)
 	}
-	if hair["Label"] != "headfeature/hair/hair_bangs" || hair["Imp_HeadCon_Node"] != "hfx_hair_bangs" || hair["Type_FD"] != "D" {
+	if hair["Label"] != "head_features/hair/hair_bangs" || hair["Imp_HeadCon_Node"] != "hfx_hair_bangs" || hair["Type_FD"] != "D" {
 		t.Fatalf("unexpected head feature defaults: %#v", hair)
 	}
 
-	if _, ok := got[0].LockData["visualeffects:headaccessory/hat/bandana"]; !ok {
+	if _, ok := got[0].LockData["visualeffects:head_accessories/hat/bandana"]; !ok {
 		t.Fatalf("expected head accessory lock id, got %#v", got[0].LockData)
 	}
-	if _, ok := got[0].LockData["visualeffects:headdecoration/laurel/laurel"]; !ok {
+	if _, ok := got[0].LockData["visualeffects:head_decorations/laurel/laurel"]; !ok {
 		t.Fatalf("expected head decoration lock id, got %#v", got[0].LockData)
 	}
-	if _, ok := got[0].LockData["visualeffects:headfeature/hair/hair_bangs"]; !ok {
+	if _, ok := got[0].LockData["visualeffects:head_features/hair/hair_bangs"]; !ok {
 		t.Fatalf("expected head feature lock id, got %#v", got[0].LockData)
 	}
 }
@@ -7412,8 +7412,8 @@ func TestApplyAutogenConsumersAugmentsHeadVisualeffectsFromLocalOverride(t *test
 func TestApplyAutogenConsumersUsesFolderDrivenSlashHeadVisualeffectsNames(t *testing.T) {
 	root := testProjectRoot(t)
 	overrideRoot := filepath.Join(root, "autogen-assets")
-	mkdirAll(t, filepath.Join(overrideRoot, "vfxs", "headfeature", "sinfar", "ears_plt"))
-	writeFile(t, filepath.Join(overrideRoot, "vfxs", "headfeature", "sinfar", "ears_plt", "hfx_Ear_EL_L.mdl"), "mdl\n")
+	mkdirAll(t, filepath.Join(overrideRoot, "vfxs", "head_features", "sinfar", "ears_plt"))
+	writeFile(t, filepath.Join(overrideRoot, "vfxs", "head_features", "sinfar", "ears_plt", "hfx_Ear_EL_L.mdl"), "mdl\n")
 
 	p := testProject(root)
 	p.Config.Autogen.Consumers = []project.AutogenConsumerConfig{
@@ -7423,13 +7423,13 @@ func TestApplyAutogenConsumersUsesFolderDrivenSlashHeadVisualeffectsNames(t *tes
 			Dataset:           "visualeffects",
 			Mode:              "head_visualeffects",
 			Root:              "vfxs",
-			Include:           []string{"headfeature/**/*.mdl"},
+			Include:           []string{"head_features/**/*.mdl"},
 			Derive:            project.AutogenDeriveConfig{Kind: "model_stem", GroupFrom: "first_path_segment"},
 			Manifest:          project.AutogenManifestConfig{ReleaseTag: "head-vfx-manifest-current", AssetName: "sow-head-vfx-manifest.json", CacheName: "sow-head-vfx-manifest.json"},
 			LocalOverrideRoot: "autogen-assets",
 			HeadVisualeffects: project.HeadVisualeffectsConfig{
 				Groups: map[string]project.HeadVisualeffectGroupConfig{
-					"headfeature": {
+					"head_features": {
 						ModelColumns: []string{"Imp_HeadCon_Node", "Imp_Root_H_Node"},
 					},
 				},
@@ -7455,7 +7455,7 @@ func TestApplyAutogenConsumersUsesFolderDrivenSlashHeadVisualeffectsNames(t *tes
 			Columns: []string{"Label", "Type_FD", "OrientWithGround", "Imp_HeadCon_Node", "Imp_Root_H_Node", "OrientWithObject"},
 			Rows:    nil,
 			LockData: map[string]int{
-				"visualeffects:headfeature/ears_plt/Ear_EL_L": 11030,
+				"visualeffects:head_features/ears_plt/Ear_EL_L": 11030,
 			},
 		},
 	}
@@ -7468,13 +7468,13 @@ func TestApplyAutogenConsumersUsesFolderDrivenSlashHeadVisualeffectsNames(t *tes
 		t.Fatalf("expected one autogenerated visualeffects row, got %#v", got)
 	}
 	row := got[0].Rows[0]
-	if row["key"] != "visualeffects:headfeature/ears_plt/Ear_EL_L" {
+	if row["key"] != "visualeffects:head_features/ears_plt/Ear_EL_L" {
 		t.Fatalf("expected folder-driven key, got %#v", row)
 	}
 	if row["id"] != 11030 {
 		t.Fatalf("expected existing lock id to be preserved, got %#v", row)
 	}
-	if row["Label"] != "headfeature/ears_plt/Ear_EL_L" {
+	if row["Label"] != "head_features/ears_plt/Ear_EL_L" {
 		t.Fatalf("expected preserve-case slash label, got %#v", row)
 	}
 	if row["Imp_HeadCon_Node"] != "hfx_Ear_EL_L" || row["Imp_Root_H_Node"] != "hfx_Ear_EL_L" {
@@ -7487,7 +7487,7 @@ func TestBuildNativeUsesConfiguredHeadVisualeffectsGroups(t *testing.T) {
 	mkdirAll(t, filepath.Join(root, "src"))
 	mkdirAll(t, filepath.Join(root, "build"))
 	mkdirAll(t, filepath.Join(root, "topdata", "data", "visualeffects"))
-	mkdirAll(t, filepath.Join(root, "autogen-assets", "vfxs", "chestaccessory"))
+	mkdirAll(t, filepath.Join(root, "autogen-assets", "vfxs", "chest_accessories"))
 	mkdirAll(t, filepath.Join(root, "autogen-assets", "vfxs", "head_jewels"))
 	writeFile(t, filepath.Join(root, "topdata", "base_dialog.json"), "{}\n")
 	writeFile(t, filepath.Join(root, "topdata", "data", "visualeffects", "base.json"), `{
@@ -7495,7 +7495,7 @@ func TestBuildNativeUsesConfiguredHeadVisualeffectsGroups(t *testing.T) {
   "columns": ["Label", "Type_FD", "OrientWithGround", "Imp_HeadCon_Node", "Imp_Root_S_Node", "Imp_Root_M_Node", "Imp_Root_L_Node", "Imp_Root_H_Node", "OrientWithObject"],
   "rows": []
 }`+"\n")
-	writeFile(t, filepath.Join(root, "autogen-assets", "vfxs", "chestaccessory", "tfx_sash.mdl"), "mdl\n")
+	writeFile(t, filepath.Join(root, "autogen-assets", "vfxs", "chest_accessories", "tfx_sash.mdl"), "mdl\n")
 	writeFile(t, filepath.Join(root, "autogen-assets", "vfxs", "head_jewels", "hfx_circlet.mdl"), "mdl\n")
 	writeFile(t, filepath.Join(root, "nwn-tool.yaml"), `
 module:
@@ -7515,7 +7515,7 @@ autogen:
       mode: head_visualeffects
       root: vfxs
       include:
-        - chestaccessory/**/*.mdl
+        - chest_accessories/**/*.mdl
         - head_jewels/**/*.mdl
       derive:
         kind: model_stem
@@ -7527,8 +7527,8 @@ autogen:
       local_override_root: autogen-assets
       head_visualeffects:
         groups:
-          chestaccessory:
-            prefix: chestaccessory
+          chest_accessories:
+            prefix: chest_accessories
             model_columns:
               - Imp_Root_S_Node
               - Imp_Root_M_Node
@@ -7561,7 +7561,7 @@ autogen:
 	}
 	text := string(visualeffectsBytes)
 	for _, want := range []string{
-		"0\tchestaccessory_sash\tF\t0\t****\ttfx_sash\ttfx_sash\ttfx_sash\ttfx_sash\t0",
+		"0\tchest_accessories_sash\tF\t0\t****\ttfx_sash\ttfx_sash\ttfx_sash\ttfx_sash\t0",
 		"1\theadjewel_circlet\tF\t0\thfx_circlet\t****\t****\t****\t****\t0",
 	} {
 		if !strings.Contains(text, want) {
@@ -7572,16 +7572,16 @@ autogen:
 
 func TestBuildGenerated2DAAssetsAppendsCachedModelsFromHeadVisualeffects(t *testing.T) {
 	root := testProjectRoot(t)
-	mkdirAll(t, filepath.Join(root, "assets", "vfxs", "chestaccessory"))
-	mkdirAll(t, filepath.Join(root, "assets", "vfxs", "headaccessory"))
-	mkdirAll(t, filepath.Join(root, "assets", "vfxs", "headdecoration"))
-	mkdirAll(t, filepath.Join(root, "assets", "vfxs", "headfeature", "hair"))
+	mkdirAll(t, filepath.Join(root, "assets", "vfxs", "chest_accessories"))
+	mkdirAll(t, filepath.Join(root, "assets", "vfxs", "head_accessories"))
+	mkdirAll(t, filepath.Join(root, "assets", "vfxs", "head_decorations"))
+	mkdirAll(t, filepath.Join(root, "assets", "vfxs", "head_features", "hair"))
 	mkdirAll(t, filepath.Join(root, "topdata", "data", "cachedmodels"))
-	writeFile(t, filepath.Join(root, "assets", "vfxs", "chestaccessory", "tfx_sash.mdl"), "mdl\n")
-	writeFile(t, filepath.Join(root, "assets", "vfxs", "headaccessory", "hfx_bandana.mdl"), "mdl\n")
-	writeFile(t, filepath.Join(root, "assets", "vfxs", "headaccessory", "hfx_existing.mdl"), "mdl\n")
-	writeFile(t, filepath.Join(root, "assets", "vfxs", "headdecoration", "hfx_laurel.mdl"), "mdl\n")
-	writeFile(t, filepath.Join(root, "assets", "vfxs", "headfeature", "hair", "hfx_hair_bangs.mdl"), "mdl\n")
+	writeFile(t, filepath.Join(root, "assets", "vfxs", "chest_accessories", "tfx_sash.mdl"), "mdl\n")
+	writeFile(t, filepath.Join(root, "assets", "vfxs", "head_accessories", "hfx_bandana.mdl"), "mdl\n")
+	writeFile(t, filepath.Join(root, "assets", "vfxs", "head_accessories", "hfx_existing.mdl"), "mdl\n")
+	writeFile(t, filepath.Join(root, "assets", "vfxs", "head_decorations", "hfx_laurel.mdl"), "mdl\n")
+	writeFile(t, filepath.Join(root, "assets", "vfxs", "head_features", "hair", "hfx_hair_bangs.mdl"), "mdl\n")
 	writeFile(t, filepath.Join(root, "topdata", "data", "cachedmodels", "base.json"), `{
   "columns": ["Model"],
   "rows": [
@@ -7603,7 +7603,7 @@ func TestBuildGenerated2DAAssetsAppendsCachedModelsFromHeadVisualeffects(t *test
 				ID:      "cachedmodels",
 				Mode:    "cachedmodels_rows",
 				Root:    "vfxs",
-				Include: []string{"chestaccessory/**/*.mdl", "headaccessory/**/*.mdl", "headdecoration/**/*.mdl", "headfeature/**/*.mdl"},
+				Include: []string{"chest_accessories/**/*.mdl", "head_accessories/**/*.mdl", "head_decorations/**/*.mdl", "head_features/**/*.mdl"},
 				Derive:  project.AutogenDeriveConfig{Kind: "model_stem", GroupFrom: "first_path_segment"},
 			},
 		},
@@ -12808,10 +12808,10 @@ func TestBuildNativeWithReleasedHeadVisualeffectsManifest(t *testing.T) {
   "generated_at": "2026-04-25T00:00:00Z",
   "head_visualeffects": {
     "groups": {
-      "headaccessory": {
+      "head_accessories": {
         "model_columns": ["Imp_HeadCon_Node", "Imp_Root_H_Node"]
       },
-      "headfeature": {
+      "head_features": {
         "model_columns": ["Imp_HeadCon_Node", "Imp_Root_H_Node"]
       }
     },
@@ -12830,14 +12830,14 @@ func TestBuildNativeWithReleasedHeadVisualeffectsManifest(t *testing.T) {
   },
   "entries": [
     {
-      "group": "headaccessory",
+      "group": "head_accessories",
       "model_stem": "hfx_bandana",
-      "source": "headaccessory/hfx_bandana.mdl"
+      "source": "head_accessories/hfx_bandana.mdl"
     },
     {
-      "group": "headfeature",
+      "group": "head_features",
       "model_stem": "hfx_hair_bangs",
-      "source": "headfeature/hair/hfx_hair_bangs.mdl"
+      "source": "head_features/hair/hfx_hair_bangs.mdl"
     }
   ]
 }` + "\n"
@@ -12877,7 +12877,7 @@ func TestBuildNativeWithReleasedHeadVisualeffectsManifest(t *testing.T) {
 						Dataset:  "visualeffects",
 						Mode:     "head_visualeffects",
 						Root:     "vfxs",
-						Include:  []string{"headaccessory/**/*.mdl", "headfeature/**/*.mdl"},
+						Include:  []string{"head_accessories/**/*.mdl", "head_features/**/*.mdl"},
 						Derive: project.AutogenDeriveConfig{
 							Kind:      "model_stem",
 							GroupFrom: "first_path_segment",
@@ -12904,8 +12904,8 @@ func TestBuildNativeWithReleasedHeadVisualeffectsManifest(t *testing.T) {
 	}
 	text := string(visualeffectsBytes)
 	for _, want := range []string{
-		"0\theadaccessory/bandana\tD\t0\thfx_bandana\thfx_bandana\t1",
-		"1\theadfeature/hair/hair_bangs\tD\t0\thfx_hair_bangs\thfx_hair_bangs\t1",
+		"0\thead_accessories/bandana\tD\t0\thfx_bandana\thfx_bandana\t1",
+		"1\thead_features/hair/hair_bangs\tD\t0\thfx_hair_bangs\thfx_hair_bangs\t1",
 		"17\tEXISTING\tF\t0\t****\t****\t0",
 	} {
 		if !strings.Contains(text, want) {
@@ -12932,7 +12932,7 @@ func TestBuildNativePrefersRemoteReleasedHeadVisualeffectsManifestOverFreshCache
 }`+"\n")
 	writeFile(t, filepath.Join(projRoot, "topdata", "data", "visualeffects", "lock.json"), `{
   "visualeffects:existing": 17,
-  "visualeffects:headaccessory/bandana": 42
+  "visualeffects:head_accessories/bandana": 42
 }`+"\n")
 	mkdirAll(t, filepath.Join(projRoot, "reference"))
 	writeFile(t, filepath.Join(projRoot, "reference", "build.py"), "print('ok')\n")
@@ -12943,9 +12943,9 @@ func TestBuildNativePrefersRemoteReleasedHeadVisualeffectsManifestOverFreshCache
   "generated_at": "2026-04-25T00:00:00Z",
   "entries": [
     {
-      "group": "headfeature",
+      "group": "head_features",
       "model_stem": "hfx_hair_bangs",
-      "source": "headfeature/hair/hfx_hair_bangs.mdl"
+      "source": "head_features/hair/hfx_hair_bangs.mdl"
     }
   ]
 }`+"\n")
@@ -12959,9 +12959,9 @@ func TestBuildNativePrefersRemoteReleasedHeadVisualeffectsManifestOverFreshCache
   "generated_at": "2026-04-25T12:00:00Z",
   "entries": [
     {
-      "group": "headaccessory",
+      "group": "head_accessories",
       "model_stem": "hfx_bandana",
-      "source": "headaccessory/hfx_bandana.mdl"
+      "source": "head_accessories/hfx_bandana.mdl"
     }
   ]
 }` + "\n"
@@ -13001,7 +13001,7 @@ func TestBuildNativePrefersRemoteReleasedHeadVisualeffectsManifestOverFreshCache
 						Dataset:  "visualeffects",
 						Mode:     "head_visualeffects",
 						Root:     "vfxs",
-						Include:  []string{"headaccessory/**/*.mdl", "headfeature/**/*.mdl"},
+						Include:  []string{"head_accessories/**/*.mdl", "head_features/**/*.mdl"},
 						Derive: project.AutogenDeriveConfig{
 							Kind:      "model_stem",
 							GroupFrom: "first_path_segment",
@@ -13027,7 +13027,7 @@ func TestBuildNativePrefersRemoteReleasedHeadVisualeffectsManifestOverFreshCache
 		t.Fatalf("read visualeffects.2da: %v", err)
 	}
 	text := string(visualeffectsBytes)
-	if !strings.Contains(text, "42\theadaccessory/bandana\tD\t0\thfx_bandana\t1") {
+	if !strings.Contains(text, "42\thead_accessories/bandana\tD\t0\thfx_bandana\t1") {
 		t.Fatalf("expected remote manifest entry with preserved lock id, got:\n%s", text)
 	}
 	if strings.Contains(text, "HAIR_BANGS") {
@@ -13052,7 +13052,7 @@ func TestBuildPackageInvalidatesFreshAutogenCacheWhenReleaseAssetIsNewer(t *test
 	setCompiledOutputTimes(t, result, outputTime)
 
 	cachePath := filepath.Join(root, ".cache", "sow-head-vfx-manifest.json")
-	writeFile(t, cachePath, `{"id":"head_visualeffects","generated_at":"2026-04-25T10:00:00Z","entries":[{"group":"headaccessory","model_stem":"hfx_bandana","source":"headaccessory/hfx_bandana.mdl"}]}`+"\n")
+	writeFile(t, cachePath, `{"id":"head_visualeffects","generated_at":"2026-04-25T10:00:00Z","entries":[{"group":"head_accessories","model_stem":"hfx_bandana","source":"head_accessories/hfx_bandana.mdl"}]}`+"\n")
 	setFileTime(t, cachePath, time.Now())
 
 	var server *httptest.Server
@@ -13063,7 +13063,7 @@ func TestBuildPackageInvalidatesFreshAutogenCacheWhenReleaseAssetIsNewer(t *test
 			_, _ = w.Write([]byte(`{"assets":[{"name":"sow-head-vfx-manifest.json","updated_at":"3026-04-25T12:00:00Z","browser_download_url":"` + server.URL + `/downloads/sow-head-vfx-manifest.json"}]}`))
 		case "/downloads/sow-head-vfx-manifest.json":
 			w.Header().Set("Content-Type", "application/json")
-			_, _ = w.Write([]byte(`{"id":"head_visualeffects","entries":[{"group":"headaccessory","model_stem":"hfx_bandana","source":"headaccessory/hfx_bandana.mdl"}]}`))
+			_, _ = w.Write([]byte(`{"id":"head_visualeffects","entries":[{"group":"head_accessories","model_stem":"hfx_bandana","source":"head_accessories/hfx_bandana.mdl"}]}`))
 		default:
 			http.NotFound(w, r)
 		}
@@ -13081,7 +13081,7 @@ func TestBuildPackageInvalidatesFreshAutogenCacheWhenReleaseAssetIsNewer(t *test
 			Mode:     "head_visualeffects",
 			Optional: true,
 			Root:     "vfxs",
-			Include:  []string{"headaccessory/**/*.mdl", "headfeature/**/*.mdl"},
+			Include:  []string{"head_accessories/**/*.mdl", "head_features/**/*.mdl"},
 			Derive: project.AutogenDeriveConfig{
 				Kind:      "model_stem",
 				GroupFrom: "first_path_segment",
@@ -13406,7 +13406,7 @@ func TestBuildPackageFailsWhenAutogenManifestCacheIsStale(t *testing.T) {
 			Mode:     "head_visualeffects",
 			Optional: true,
 			Root:     "vfxs",
-			Include:  []string{"headaccessory/**/*.mdl", "headfeature/**/*.mdl"},
+			Include:  []string{"head_accessories/**/*.mdl", "head_features/**/*.mdl"},
 			Derive: project.AutogenDeriveConfig{
 				Kind:      "model_stem",
 				GroupFrom: "first_path_segment",
@@ -13419,7 +13419,7 @@ func TestBuildPackageFailsWhenAutogenManifestCacheIsStale(t *testing.T) {
 		},
 	}
 	cachePath := filepath.Join(root, ".cache", "sow-head-vfx-manifest.json")
-	writeFile(t, cachePath, `{"id":"head_visualeffects","entries":[{"group":"headaccessory","model_stem":"hfx_bandana","source":"headaccessory/hfx_bandana.mdl"}]}`+"\n")
+	writeFile(t, cachePath, `{"id":"head_visualeffects","entries":[{"group":"head_accessories","model_stem":"hfx_bandana","source":"head_accessories/hfx_bandana.mdl"}]}`+"\n")
 	setFileTime(t, cachePath, time.Now().Add(-2*autogenManifestCacheMaxAge))
 
 	if _, err := BuildPackage(proj, nil); err == nil || !strings.Contains(err.Error(), "older than source file") {
@@ -14354,7 +14354,7 @@ func testProject(root string) *project.Project {
 						Mode:     "head_visualeffects",
 						Optional: true,
 						Root:     "vfxs",
-						Include:  []string{"headaccessory/**/*.mdl", "headfeature/**/*.mdl"},
+						Include:  []string{"head_accessories/**/*.mdl", "head_features/**/*.mdl"},
 						Derive: project.AutogenDeriveConfig{
 							Kind:      "model_stem",
 							GroupFrom: "first_path_segment",