Only thing impossible during a WO is 48+, everything else is. It's even easier to manage GS minutes with a WO.
At least, 48+ in a single position. You can certainly get 53 minutes of training for two position training for one player by setting him as starter, backup, reserve at one training position and then backup at the other. I suppose in theory you could get one player 51 minutes and another 47 in a three position training by having one be starter and backup at position 1 and backup at 2, while another is starter+backup+reserve in position 3 and reserve in position 1 and 2. Granted, you'd probably need to have a very unique situation to do that (end of season auto-scrimmage against a league opponent with five guys needing one last bit of training in a skill, maybe).