IMO protein loving/ sensitive is a spectrum - protein is wonderful for fine hairs and porous hair BUT it can be drying in excess, and porous hair is easily dried out. Balance is key for almost everyone.
Do be aware hydrolysed protein had two major roles - it can penetrate as far as the cortex and can coat the surface acting as a film former. There are slightly different effects from each.
My hair is currently loving a protein rich leave in almost every wash but it likes just a little oil in the mix, a few washes without any oil and I lose all the protein benefits. Balance! I don't think it's that my hair likes or dislikes the amount of protein, it just does like too much left on the surface drying it out, again that seems to work best in balance with emollients.
And for me the protein does not work at all with every styler, DISASTER with my favourite humectant (propylene glycol) rich gel. Individually great but so not together, I get frizz and lose the clumps. If conditioner only works for you go for it.
2a-2c, medium texture, porous/ colour treated. Three years CG, growing out mechanical and chemical damage = breakage and very high porosity. Past armpit length heading for waist.
Treatments: Komaza protein, Komaza Matani, coconut oil with sugar syrup. Hairveda Sitrinillah
Leave in: Fructis Sleek & Shine (old), Gliss ultimate volume
Styler: Umberto Giannini jelly, Boots curl creme, Rockin RInglets
Experimenting with: Mega-Tek, Curl Harmony reviver, Elvive Full Restore 5.