I'm coarse and porous as well. Like Rimi, I have to be careful with my protein use.
My hair only seems to tolerate keratin protein. Other people will find different proteins that they can tolerate. You will have to experiment to see what your hair likes.
I also find in my hair tolerates much more protein in high dewpoints than it does in low dewpoints.
In the winter, when the dewpoints are low, my hair needs much more moisture, and doesn't need any protein. In the summer, my high porosity makes my hair more prone to frizz, and protein seems to help that. Also, when the dewpoints are high, my hair seems to need less moisture. But, if it does need some moisture to help keep frizz at bay.
What helps me the most in extreme weather conditions is oil sealing. There are threads about that if you want to search them. Essentially, I put oil on my hair on top of my leave in and underneath my gel.
Siri types my posts for me.
Med/Coarse, porous curly.