I've never heard of frizz being an indicator of porosity. All curly/wavy hair has some frizz, it's the nature of the beast. Lessening frizz has to do with the right protein/moisture balance and the right styling products. My hair is definitely low porosity and it frizzes.
While heat styling and chemicals can damage hair, some folks just have porous hair. Just by the drying time, it appears as if your hair is low porosity.
3a (Corkicelli), highlighted, fine, low porosity
modified CG, since April '07
CG since 3/11/08
HGs: Anything Sevi; Curly Kinks Satin Roots, Curlycue ReNew and Coil Jam; homemade FSG and okra gel; soap bars; UFD Curly Magic; Botanical Spirits Jellies, CJ Repair Me