first one didn't work, let's try this...

fuzzing/coverage/coverage_maps.go

@@ -16,6 +16,10 @@ type CoverageMaps struct {
 	// maps represents a structure used to track every ContractCoverageMap by a given deployed address/lookup hash.
 	maps map[common.Hash]map[common.Address]*ContractCoverageMap
 
+	// TODO comment this
+	// The assumption here is that geth codehash matches if and only if codehash matches
+	gethCodeHashToCodeHash map[common.Hash]*common.Hash
+
 	// TODO comment this
 	// The assumption here is that geth codehash matches if and only if codehash matches
 	cachedGethCodeHash common.Hash
@@ -40,7 +44,9 @@ type CoverageMaps struct {
 
 // NewCoverageMaps initializes a new CoverageMaps object.
 func NewCoverageMaps() *CoverageMaps {
-	maps := &CoverageMaps{}
+	maps := &CoverageMaps{
+		gethCodeHashToCodeHash: make(map[common.Hash]*common.Hash),
+	}
 	maps.Reset()
 	return maps
 }

fuzzing/coverage/coverage_tracer.go

@@ -52,6 +52,9 @@ type CoverageTracer struct {
 
 	// nativeTracer is the underlying tracer used to capture EVM execution.
 	nativeTracer *chain.TestChainTracer
+
+	// TODO comment
+	gethCodeHashToCodeHash map[common.Hash]*common.Hash
 }
 
 // coverageTracerCallFrameState tracks state across call frames in the tracer.
@@ -70,6 +73,7 @@ type coverageTracerCallFrameState struct {
 func NewCoverageTracer() *CoverageTracer {
 	tracer := &CoverageTracer{
 		coverageMaps:    NewCoverageMaps(),
+		gethCodeHashToCodeHash: make(map[common.Hash]*common.Hash),
 		callFrameStates: make([]*coverageTracerCallFrameState, 0),
 	}
 	nativeTracer := &tracers.Tracer{
@@ -167,9 +171,15 @@ func (t *CoverageTracer) OnOpcode(pc uint64, op byte, gas, cost uint64, scope tr
 			if callFrameState.pendingCoverageMap.cachedGethCodeHash == gethCodeHash {
 				lookupHash := callFrameState.pendingCoverageMap.cachedCodeHash
 				callFrameState.lookupHash = &lookupHash
+			} else if t.gethCodeHashToCodeHash[gethCodeHash] != nil {
+				callFrameState.lookupHash = t.gethCodeHashToCodeHash[gethCodeHash]
+			} else if callFrameState.pendingCoverageMap.gethCodeHashToCodeHash[gethCodeHash] != nil {
+				callFrameState.lookupHash = t.gethCodeHashToCodeHash[gethCodeHash]
 			} else {
 				lookupHash := getContractCoverageMapHash(code, callFrameState.create)
 				callFrameState.lookupHash = &lookupHash
+				t.gethCodeHashToCodeHash[gethCodeHash] = &lookupHash
+				callFrameState.pendingCoverageMap.gethCodeHashToCodeHash[gethCodeHash] = &lookupHash
 			}
 		}