Today I wanted to do another experiment with next mosfet. Only to find out that my experimentorture circuit is measuring some nonsense. DOH!
It turns out that I've blown the TL431 ic when setting up the datalogger, and it is a dead short in all directions. This means my previous experiment is completely and totally broken, and I will put a note there right now.
That mosfet apparently was tortured to near death, with gate threshold voltage (1 mA) measuring 0.708 V, and with substantial conductivity at zero gate voltage.