I don't know how long it takes to do wye trip. I think 30 minutes is "over-statement" due to low speed and stops. Even in LAX for non-revenue runs, Amtrak long distance trains have to back up from the shop to the station, or using switcher locomotive. I don't know who do the front (last car of train) while in reverse, maybe the conductor using radio with engineer in locomotive. Problem with wye at ABQ is you'll need one more crew- hand-thrown switch, about 3 switches or so in the wye area. Upgrading to remote control is possible, but expensive.