Body replacement cbms

I see the idea of ,cbms that take up so much of your body where you don’t naturally heal and need to actively repair them, a lot. This is a very cool idea, but with a drawback so big there would need to be a big enough bonus to use them. I think a cool idea would to have arms and legs be equipable so you could have the ability to swap out a fusion blaster arm with a jackhammer arm or a springy roadrunner legs with treads. it would also add a tactical decision between some mutations and cbms. because you cant have tentacle legs and tank treads at the same time. what are your thoughts