Using Retul I can get the same knee opening with an 800mm seatheight and 110mm of setback, 770mm seat height and 95mm of setback, or 785mm seat height and 80mm of setback. All of these fit options are very, very different. FWIW I ride the last one and determined it through trial and error. Checked it with Retul and bam, it gives almost the same angles, but the cleats feel better, im more balanced, and have no hip rocking of any sort.
Interesting experiments you've done. I've recently done changes to but the 2 changes you've done after your 800mm saddle height also have less setback.
Have i read that right?
If so i would've thought your knee angle to increase.
Anyway nice to see others experimenting like this.