No, you're right; warranties are non-transferable. Still might not be a bad idea to not experiment with things that aren't intended to fit together.

Andto answeryour original question... my feelings are shared by many that the '06 Allegiance is/was one of the finest bows ever made. I spent half an hour at the ATA show attempting to convince the lead designer to come out with another Allegiance with the current grip but with the heavier '06 riser. He didn't buy it, but I'm not done trying...