Regeneration mutation makes you into a meatcube when gibbed

[MoonJesus]

Or maybe if you're thrown into the crusher or a gibber with regen you should come out as a limbless nugget or a living head, and slowly regrow your organs/limbs.

Also if you have synchonized biomasss you should be able to use it while handcuffed

Also lizardmen should have a much slower innate regeneration mutation due to being reptiles