I'm not so sure that it's a good idea. Isn't it true that back dragging with the FEL is much harder on the cylinders? And of course when you are digging with the BH, sometimes it will want to pull the tractor backwards towards the trench, which is kind of like back dragging, and will put a lot of force on the FEL cylinders. Just a thought.
If you read your operators manual, (BX23S page 75, section 2) it states the proper use of the bucket position, in which it DOES say:
"When possible, the loader bucket cutting edge should be lowered vertically into the ground surface"