After getting the final rank of Iron Fist, I was excited to hop into my power armor and paralyze some enemies while pummeling them. In power armor during VATS, trying to activate a critical results in my character standing there like a hulking idiot instead, and the critical attack gets skipped every time.
After maxing Iron Fist, this prevents ANY unarmed critical attacks and resulting paralyzing palm in power armor.
As a side note: knuckles and more surprisingly, power fists cannot be equipped with power armor, was this intentional because of the arm piece mods?