Bolares
Legend
Yeah, the Mountain dwarf would be really good. But I'd still allow it because of my bias towards my own mountain dwarf abjuration wizards... and how I'd love for him to be able to trade his +2 to a +1 in INT hahahahaIn that case I can't think of any edge cases where your setup doesn't allow any stat distributions that would normally be possible.
So the only possible thing you'd have to look out for are class and race synergies. Mountain dwarf gets to bring medium armour proficiency to any class without worrying about lacking stats. For some classes like the wizard that can be worth 2 feats. But honestly armoured dwarf battle mages to me is a cool concept. I'd allow it and monitor to see how it actually plays out.
Also realized I haven't said it yet. I like this idea. Just allowing non-typical races for classes without nerfing them allows for so much more character customization.