Oh boy, I have some work to do. Mr. Horn's video was right on-point - I thought I was doing things properly but can barely get in that position for a few moments with straight wrists, let alone to squat with weight on the bar. I had to lose the required straight wrists and back tightness to get the bar in position, removing the 'shelf'.

I'll keep stretching that out on a daily basis, but continue my LP with a high bar squat. I'll do as many warm-up sets as I can stand in the low bar position, with the eventual goal of finishing all work sets in the low bar position ASAP. Last night that was low bar for two sets of 5 with the empty bar, then my shoulders were done.

Thanks again for the assistance!