I think it's a waste of time and wire. You did ask

Seriously, the 'advantage' in the setup you're talking about is simply a lower current draw per channel (same at the outlet more or less) on an amplifier that would happily drive the whole load. Both channels see the same input signal and are (ideally) producing the same voltage output, with current draw split between them. Since it's all in the same amp it's even more pointless than usual.

If you want more power get a bigger amp (the 755 looks to be a good amp) and hook it up.