However, all this talk of tiny effects one way or the other is swamped by the swirling airflow that the airframe is immersed in with a traditional prop on the front.
Quite. And gusts too.
I spin the supercub from time to time, solo only because of CG limitations, and I can only make it go with the prop. On a straight stall it won't drop a wing at all in calm air, even leaving some power on, and to get it in to a spin takes a hefty bootfull of rudder. I'd be interested to know if the 90 and 135 hp versions are the same (mine is a 150, I haven't tried with the 180)