As far as a “cap” is concerned there /sorta/ is one for mutations. Once you’ve filled out the tree, you have two choices: Sit comfortably -OR- Make some purifier and start again. Non-specific mutigen has a fairly high chance of sticking you in the slime tree, which isn’t very desirable. By itself, Mutigen and Purifier is fairly rare to come by, alternatively you can make it (or tree specific mutagen) both require a fairly high cooking skill as well as some difficult to acquire materials. (To my knowledge, the only way to acquire Ammonia and Bleach in large amounts is to clear a lab, or raid every single house in a medium to large sized town/city and hope for the best.) and then you need some form of tainted stuff. (Mutated Limbs, Mutated Fetus, Zed Meat, Plant “meat”)
As far as bionics are concerned, that’s another one that’s controlled by skill, but also power. Let’s assume you can successfully install (and use) every single bionic without fucking up any of the installations and ending up with malfunctioning bionics or power loss. The only way to use those bionics is with power. And even if you install every single bionic, not one of them comes with their own power storage. Your only hope of getting any power boosts is to dig through labs, or butcher shocker zeds in hopes of finding a storage battery, then if you’re lucky you can disassemble it and make more assuming you get it right on the first try.
Otherwise you’re left to trying to boost your power high enough to get more than a few seconds out of your cloaking CBM.