I also have low and medium porosity hair which absolutely hates protein. I've been known to dye my hair pretty often, yet it will only accept/be okay with protein once in a while. My hair will feel like straw-the back will feel slightly better as it's medium porosity zone there. I, too, have pondered the usage of protein so many times. About two months ago I overdid it with protein and my hair felt sad and frizzy for a while. No bueno.
My hair tends to love: honey, oils, water, ceramides, dye
4s/3s kinks and curls. CG, Coarse and medium strands, Low and normal porosity, High Density.