diff --git a/font-src/glyphs/common/derivatives.ptl b/font-src/glyphs/common/derivatives.ptl
index 0085b34fe..d170c4df4 100644
--- a/font-src/glyphs/common/derivatives.ptl
+++ b/font-src/glyphs/common/derivatives.ptl
@@ -8,17 +8,16 @@ extern Map
 glyph-module
 
 glyph-block Common-Derivatives : begin
-	glyph-block-export ApplyCv
 	define [ApplyCv g shapeFrom follow para] : begin
-		foreach { kPrime prime } para.variants.primes : foreach h [prime.variants.values] : begin
-			local suffix : h.resolveFor para follow
-			if suffix : begin
+		foreach { kPrime prime } para.variants.primes : foreach pv [prime.variants.values] : begin
+			local suffix : pv.resolveFor para follow
+			if (para.enableCvSs && pv.tag && pv.rank && suffix) : begin
 				local dstName : shapeFrom + '.' + suffix
 				local dst : glyphStore.queryByName dstName
 				if dst : g.dependsOn dst
-				if (para.enableCvSs && h.tag && h.rank) : begin
-					[Cv h.tag h.rank h.groupRank h.description].set g dstName
-					if h.nonDeriving : [Cv h.tag h.rank].setPreventDeriving g
+
+				pv.set g dstName
+				if pv.nonDeriving : pv.setPreventDeriving g
 
 	glyph-block-export select-variant
 	define [select-variant] : with-params [name unicode [shapeFrom name] [follow name] [reduction null]] : begin
diff --git a/font-src/otl/gsub-cv-ss.ptl b/font-src/otl/gsub-cv-ss.ptl
index dae7d997e..d46647473 100644
--- a/font-src/otl/gsub-cv-ss.ptl
+++ b/font-src/otl/gsub-cv-ss.ptl
@@ -1,6 +1,6 @@
 $$include '../meta/macros.ptl'
 
-import [Cv AnyCv CvDecompose RightDependentLink RightDependentTrigger] from"../support/gr.mjs"
+import [AnyCv CvDecompose] from"../support/gr.mjs"
 
 extern Map
 extern Set
@@ -89,8 +89,8 @@ export : define [buildCVSS gsub para glyphStore] : begin
 	do "cvxx"
 		local cvGrs {}
 		foreach {name prime} para.variants.primes : foreach {vn variant} prime.variants : begin
-			if (prime.tag && variant.rank) : cvGrs.push : Cv prime.tag variant.rank
-		cvGrs.sort Cv.compare
+			if (variant.tag && variant.rank) : cvGrs.push variant
+		cvGrs.sort AnyCv.compare
 
 		foreach gr [items-of cvGrs] : begin
 			local cvAlt : [cvs.get gr.tag].createAlternateSubst
@@ -106,10 +106,10 @@ export : define [buildCVSS gsub para glyphStore] : begin
 		define decomp : composition.decompose para para.variants.selectorTree
 		local ssGrs {}
 		foreach { prime pv } [items-of decomp] : if (pv.tag && pv.rank) : begin
-			ssGrs.push : Cv pv.tag pv.rank
+			ssGrs.push pv
 			local dl [cvs.get pv.tag].decompositionLookup
 			if dl : feature.addLookup dl
-		ssGrs.sort Cv.compare
+		ssGrs.sort AnyCv.compare
 
 		foreach gr [items-of ssGrs] : begin
 			local cvSingle : [cvs.get gr.tag].createSingleSubstFor gr.rank
diff --git a/font-src/support/gr.mjs b/font-src/support/gr.mjs
index b7801e22e..9be2d2358 100644
--- a/font-src/support/gr.mjs
+++ b/font-src/support/gr.mjs
@@ -146,57 +146,6 @@ export const HintClass = {
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
-const CvTagCache = new Map();
-
-export function Cv(tag, rank, groupRank, description) {
-	const key = tag + "#" + rank;
-	if (CvTagCache.has(key)) return CvTagCache.get(key);
-	const rel = {
-		tag,
-		rank,
-		groupRank,
-		description,
-		get(glyph) {
-			if (glyph && glyph.related && glyph.related.cv) return glyph.related.cv[key];
-			else return null;
-		},
-		set(glyph, toGid) {
-			if (typeof toGid !== "string") throw new Error("Must supply a GID instead of a glyph");
-			if (!glyph.related) glyph.related = {};
-			if (!glyph.related.cv) glyph.related.cv = {};
-			glyph.related.cv[key] = toGid;
-		},
-		getPreventDeriving(glyph) {
-			return (
-				glyph.related &&
-				glyph.related.preventCvDeriving &&
-				!!glyph.related.preventCvDeriving[key]
-			);
-		},
-		setPreventDeriving(glyph) {
-			if (!glyph.related) glyph.related = {};
-			if (!glyph.related.preventCvDeriving) glyph.related.preventCvDeriving = {};
-			glyph.related.preventCvDeriving[key] = true;
-		},
-		amendName(name) {
-			return name + "." + key;
-		},
-		amendOtName(name) {
-			return name + "." + tag + "-" + rank;
-		}
-	};
-	CvTagCache.set(key, rel);
-	return rel;
-}
-
-Cv.compare = function (a, b) {
-	if (a.tag < b.tag) return -1;
-	if (a.tag > b.tag) return 1;
-	if (a.rank < b.rank) return -1;
-	if (a.rank > b.rank) return 1;
-	return 0;
-};
-
 export const DotlessOrNot = {
 	query(glyph) {
 		if (Dotless.get(glyph)) return [Dotless];
@@ -208,14 +157,18 @@ export const AnyCv = {
 	query(glyph) {
 		let ret = [];
 		if (glyph && glyph.related && glyph.related.cv) {
-			for (const key in glyph.related.cv) {
-				const [tag, rankStr] = key.split("#");
-				const rank = parseInt(rankStr, 10);
-				const rel = Cv(tag, rank);
-				if (rel.get(glyph)) ret.push(rel);
+			for (const [cv, dst] of glyph.related.cv) {
+				ret.push(cv);
 			}
 		}
 		return ret;
+	},
+	compare(a, b) {
+		const ua = a.tag.toUpperCase(),
+			ub = b.tag.toUpperCase();
+		if (ua < ub) return -1;
+		if (ua > ub) return 1;
+		return a.rank - b.rank;
 	}
 };
 
@@ -223,23 +176,17 @@ export const AnyDerivingCv = {
 	query(glyph) {
 		let ret = [];
 		if (glyph && glyph.related && glyph.related.cv) {
-			for (const key in glyph.related.cv) {
-				if (glyph.related.preventCvDeriving && glyph.related.preventCvDeriving[key])
+			for (const [cv, dst] of glyph.related.cv) {
+				if (glyph.related.preventCvDeriving && glyph.related.preventCvDeriving.has(cv))
 					continue;
-				const [tag, rankStr] = key.split("#");
-				const rank = parseInt(rankStr, 10);
-				const rel = Cv(tag, rank);
-				if (rel.get(glyph)) ret.push(rel);
+				ret.push(cv);
 			}
 		}
 		return ret;
 	},
 	hasNonDerivingVariants(glyph) {
-		if (glyph && glyph.related && glyph.related.cv) {
-			for (const key in glyph.related.cv) {
-				if (glyph.related.preventCvDeriving && glyph.related.preventCvDeriving[key])
-					return true;
-			}
+		if (glyph && glyph.related && glyph.related.preventCvDeriving) {
+			return glyph.related.preventCvDeriving.size > 0;
 		}
 		return false;
 	}
@@ -278,7 +225,7 @@ export function getGrMesh(gidList, grq, fnGidToGlyph) {
 	for (const g of gidList) {
 		for (const gr of grq.query(fnGidToGlyph(g))) allGrSet.add(gr);
 	}
-	const allGrList = Array.from(allGrSet).sort(Cv.compare).reverse();
+	const allGrList = Array.from(allGrSet).sort(AnyCv.compare).reverse();
 
 	let ret = [];
 	for (const gr of allGrList) {
@@ -399,15 +346,9 @@ function displayQuerySingleFeature(gs, gid, name, grCis, sink) {
 		);
 	}
 }
-function byTagPreference(a, b) {
-	const ua = a.tag.toUpperCase(),
-		ub = b.tag.toUpperCase();
-	if (ua < ub) return -1;
-	if (ua > ub) return 1;
-	return a.rank - b.rank;
-}
+
 function queryCvFeatureTagsOf(sink, gid, glyph, tagSet) {
-	const cvs = AnyCv.query(glyph).sort(byTagPreference);
+	const cvs = AnyCv.query(glyph).sort(AnyCv.compare);
 
 	let existingFeatures = new Map();
 	let existingTargets = new Set();
diff --git a/font-src/support/variant-data.mjs b/font-src/support/variant-data.mjs
index b357be8e7..a866bd290 100644
--- a/font-src/support/variant-data.mjs
+++ b/font-src/support/variant-data.mjs
@@ -181,7 +181,7 @@ class Prime {
 	}
 }
 
-class PrimeVariant {
+export class PrimeVariant {
 	constructor(key, tag, cfg) {
 		this.key = key;
 		this.tag = tag;
@@ -200,6 +200,36 @@ class PrimeVariant {
 	resolve(para, vs) {
 		Object.assign(vs, this.selector);
 	}
+
+	// Gr methods
+	get(glyph) {
+		if (glyph && glyph.related && glyph.related.cv) return glyph.related.cv.get(this);
+		else return null;
+	}
+	set(glyph, toGid) {
+		if (typeof toGid !== "string") throw new Error("Must supply a GID instead of a glyph");
+		if (!glyph.related) glyph.related = {};
+		if (!glyph.related.cv) glyph.related.cv = new Map();
+		glyph.related.cv.set(this, toGid);
+	}
+	getPreventDeriving(glyph) {
+		return (
+			glyph.related &&
+			glyph.related.preventCvDeriving &&
+			!!glyph.related.preventCvDeriving.has(this)
+		);
+	}
+	setPreventDeriving(glyph) {
+		if (!glyph.related) glyph.related = {};
+		if (!glyph.related.preventCvDeriving) glyph.related.preventCvDeriving = new Set();
+		glyph.related.preventCvDeriving.add(this);
+	}
+	amendName(name) {
+		return name + "." + this.tag + "-" + this.rank;
+	}
+	amendOtName(name) {
+		return this.amendName(name);
+	}
 }
 
 class Composite {