It could be that Sonic Superstars' Prototype is the answer to the Metal Sonic problem. You'd have to discard Chaotix's lore but that's one way to fill things. A Prototype that can look like Metal Sonic, will later be the basis for Metal Knuckles in Sonic R.

>>535253405
????
Are you claiming that the dimensions just shift between Classic and Modern? I don't get it.