The float test is notoriously unreliable. You need to do the test where you run your fingers from tip to root. If it slips and, possibly squeaks, it's low porosity.
I was going by the length in your avatar. Possibly frequent trims would help.
You're using some products with polyquats. Maybe if you try not using them after you shampoo--see what happens. While I'm told that they don't build up, for me, they seemed to "coat" my hair and cause frizz when wet. Haven't had that problem since I've eliminated them.