Isn't wavy hair awesome?
Porosity always seems to be the hardest hair property to determine... Products can lengthen drying time greatly, so you make want to assess the drying time of your naked hair. Does your hair feel smooth when you run your fingers up a strand (from tip to scalp)? Smooth = low porosity, rough = high porosity. Damaged hair usually has high porosity. You can also kind of figure out your porosity based on how easily your hair gets wet. Easily = high, Not easily = low.
As far as protein goes, a good indicator of if your hair needs protein is based on porosity. High porosity likes protein. Fine hair also tends to like protein.
Diffusing causes my hair to get frizzy too.
You can try pixie diffusing if you haven't already, but that didn't work for me either, and I felt like it was bad for the hair dryer, turning it on and off repeatedly.
If you're exclusively cowashing, there's a chance you could be experiencing buildup from any number of things (products, hard water, pollutants, etc.), so you could always try a low poo every once in a while.
Whew, I just wrote a lot. HTH though.