My finishes are not anything to write home about, or anywhere else for that matter, but I have "sort of" removed some dings by injecting a very small amount of water under the ding then using a monokote iron to heat it. Got the idea from removing benchmarks in raw balsa before covering. Dings in polyspan respond to heat as well, as does MonoKote. Plan "B" is a well-placed decal over the Boo Boo.
Ken