only after mutations

pkg/actor/mutation_registry.go

@@ -225,10 +225,12 @@ func (r *ProtoMutationRegistry) Apply(grain any, msg ...proto.Message) ([]ApplyR
 		results = append(results, ApplyResult{Error: err, Type: rt.Name(), Mutation: m})
 	}
 
-	for _, processor := range r.processors {
-		err := processor.Process(grain)
-		if err != nil {
-			return results, err
+	if len(results) > 0 {
+		for _, processor := range r.processors {
+			err := processor.Process(grain)
+			if err != nil {
+				return results, err
+			}
 		}
 	}
 	return results, nil