An update to the problem of stuck suspension on bottom out:
On my size Medium frame, a 210x52.5mm shock does not get stuck at bottom out while a 210mmx 55mm shock jams in the bottom out position. At least one person reported that a size Large does not get stuck at bottom out while naeTech reports size Small gets stuck at bottom out at 52mm of shock stroke. The limited sample so far suggests that the problem gets worse as frames get smaller below size Large, but that's not confirmed.
I would still suggest that anyone with the frame test their bike by bottoming out the rear suspension with at a low air pressure in the shock to make sure the suspension does not jam at bottom out. Since the suspension is so progressive, you may need to reduce the air pressure in the shock to reach full bottom but you should have at least a small amount of air pressure to see the problem.