One other point Benway I have assumed that your sticking point is above the knees. All the guys I mentioned (and also Mike Cross held WR in 123s before Gant came along, ) all missed above knees,
at that point in the lft where the back is under most strain the lower back is close to 90 deg to the floor, so not actually under great load.
Most round back pullers used to pull up to the knees quickly and it often looked very easy only to stall mid thigh.
also all the guys mentioned were lame squatters, Mckee was low 500s, Kraemmer only got 500 on a good day,
If you are sticking below the knees, and you pull round, let me know