If your talking about what I think your talking about, (quick check reveals you almost certainly are) then there are some SERRIOUS negatives to CIP. People with the condition have NO WAY to know if they have been injured except to physically examine themselves thouroughly. It’s not just pain, they have essentially no feeling essential to knowing whats going on with your own body.
So basically a game with CIP would be played without any visible health bars. Player would prbably have to (e)xamine self, for several turns, at least, to see the basic health bars |||/ that normal players can glance at at any time. My understanding is that those with CIP consider it a large hasssle, and that they frequently live shorter lives, due to an inability to know what their bodies are trying to tell them.
Yeah, feeling a stubbed toe, or a sharp papercut, hurts obnoxiously, but those with CIP, don’t even know when they have someting terribly wrong. Torn mussle? metal shavings in the eye? know way to know except a close, full body examination, regualarly to make sure they aren’t bleeding out, internally or externally.
It is not a net benifit to survival, frequently things like this are used in fiction for suicide/kamakazie troops, not elite units. Elite units only ever come with something to temperarilly numb, or limit the effects of pain. Shots of morphine and adrenaline and the like, not ‘never feel anything’
as a perk, I can only seeing it as a ‘pay for perk, with player hassle’ Or as almost its own style of play, where no status effects EVER show, unless you (e)xamine for them. It would be a very different kind of play to be sure, where part of the strategy is being able to get in-and-out of fights fast enough to (e)xamine self for damage.