I always advise my clients to teach their horse to back carefully out of the trailer. It's much safer for horse and handler.
Front ramps are really for emergency only if, for example, the rear has been damaged in an accident.
Some horses want to rush out of the front, causing the handler to step down off the ramp which puts them at a disadvantage when trying to maintain control.
Remember, to put a horse's quarters one way you turn its head the opposite way as it backs.