The x-max has two locations for the spools, one inside, suitable for sensitive filament like nylon and one outside. I've had no problems with the push-back by the extruder on the outer/upper spool holder. The inner holder also has a guide for the filament which would eliminate any de-spooling problems. It's possible the problematic use did not include the internal guide, which looks like a short length of bowden tube, but isn't.