Frank - if the decal is properly "melted" then there's nothing to crack anymore - because the carrier film is dissolved and fuses with the paint. If it's cracking then it means there's still a lot of carrier film there.
I understand people are kinda afrain of Solvaset because it is so strong. Well I guess my bottle must be pretty old or something, because Solvaset often barely does the job on some of the decals I was using in the last few years. In your case I probably wouldn't be too afraid of hitting the spot with Solvaset.
Good thing is the colours you would need to touch up the spot in question are relatively easy to match.
Good luck with your build and have a nice day
Paweł