If it's in it's in! However, there may be reasons for having an aft C of G (better range and performance) or a more forward one (ground handling issues due snow or wind) - but if it's thrown back at you with no reason, then I'd suggest he load the aircraft himself. Then he can do his own loadsheet as well. Also remember the reason for the delay - Bionic Engineering: There's an arse grafted into left hand seat.
For myself, if I want specific loading, I'll ask for it well in advance and give the reason. If not, I'll take anything that falls inside the envelope.