It's still the same, absolutely no enlightenment.
I've been corresponding with the folk at Wilson Combat and they too have no idea what is causing the issue.
I've continued testing but pretty much the same results.
If I loaded a magazine with just two rounds, chambered the first and fire the second round (which at that time would be the last round) also chambered and fired.
If I loaded three rounds, chambered and fired the next round also chambered and fired but the third round (which at that time would be the last round) did not load and ended up parallel but nose to feed ramp.
The pattern continued as more rounds were added, the last round will fail to load.
I'm positive it is some thing that can be cured but I still honestly cannot see any reasonable explanation.
If the issue were related to the difference between simply manually loading the chamber and loading by recoil then it should show up when there were just two rounds in the magazine instead of only showing up when there are more than two rounds.
Next I'll mark the two magazines and take one apart to check for burrs (maybe when boring the witness holes) or other obvious issues. Hopefully I'll find some anomaly but realistically my guess is the problem will simply go away and leave me no wiser than before.