Product choosing wise, I think my texture plays a bigger role. I have fine hair and my hair loves protein, so I make sure that I get enough protein to strengthen my hair.
However porosity is important to me, too. I want to grow my hair to my hips. I have medium porosity, and I make sure it retains enough moisture. I seal my hair. I also choose some oils and products with oils that have small molecules; I want the oils to penetrate my hair and nourish/strengthen it.
All in all they're both important in their own ways
Btw yes I think you should definitely test whether your hair likes protein... the more you get to know about your hair the better, and even protein sensitive hair needs protein every now and then. Porous hair tends to like protein, but coarse hair does not. I don't know how strong the protein treatment you have in mind is?