[Autumn]

I'd assume it could be fixed by just marking your sub hand bare fist as a seperate weapon than the actual bare fist weapon, like..

Critical Hit! x attacks y with Bare Fists ® and hits them!
Critical Hit! x attacks y with Bare Fists (L) and hits them!

[Joseph Jostar]

then would someone wielding a sub-fist with MMA be able to crit twice (maybe with ambidexterity) on their sub-attack?

[Autumn]

...That is what it implies yes, this is not a balance thread, this is a bug report.