I think Sideshow follows fan discussion pretty closely and knows how unpopular the plastic is to many people. If everybody really hates the decision to use ABS, and if Sideshow felt it was absolutely necessary to pull off an armored figure without damage or distortion, then the solution from their end is easy.
No more armored figures, ever again.
If nobody wants to see a Stormtrooper or Clone with ABS then the simple decision would be not to give us one at all. If polystone is too fragile and doesn't hold a uniform scale in the molding process, which means that it can't be used for precisely fitting armored pieces, then I would be much happier never, ever getting a Clone or Stormtrooper or any other armored character in my PF collection than having to listen to the amount of negativity that Fett has produced. If they could have used polystone they would have, and then we would all be complaining that the thin chestplate pieces were broken and that the tiny little pieces on the jetpack and gauntlets were chipped and that various parts of the costume didn't fit right. So I guess they're doomed to complaints either way, and Sideshow might as well just not produce armored figures if we aren't willing to accept the different approach necessary to properly produce them.