I don't know if I'm protein sensitive per se, I just think my hair does better without a lot of protein in my hair products. I do an occasional PT (maybe 1 every couple months, mostly because I'm lazy) and my hair seems to like that.

My hair seems to like keratin the best (CJ BSC, Repair Me) and silk amino acids the least. Protein overdose doesn't always mean hard, brittle hair; sometimes it just made my hair absolutely limp and no waves!
Coarse texture, normal-high porosity, normal elasticity (Komaza Care), very weak waves
cleanser: Redken Fresh Curls Shampoo, CJ Daily Fix

rinse out: GVP Conditioning Balm, CJ Repair Me, CJ Smoothing

jellies/creams: CR Curl Maker, KCCC, UFD Curly Magic
gels: CJ CQ, BRHG