I've been thinking about materia. The use(less?) kind. Vitality, mind, all the elemental ones. Are they viable in any point? Like say I want to have so much hp when tanking, a white mage will waste all his mp just to get me at half health. Problem is, I can't meld anymore vit since tank gear is capped already.

So at what point/situation would these orbs of stats be valuable outside of selling it to the enclave for quick cash?

I could be super wrong about all of this too so feel free to correct me if I am.