Awesome!!! Here we go...

I would calibrate using the "Front" but not include your subs in the calibration. You would need to unplug the patch cords to them so YPAO cannot sense them or trigger them to come on, even if you have the bass set within the receiver to only be "Front" it will still turn the subs on. Unplug the patch cord! You will hear a completely different sound out of your mains doing this allowing YPAO to do its magic mainly on your towers and forcing your rears to mimic their performance as well, win, win. I am so confident in it because the "Front" just focuses on the problems while still allowing the mains to exercise their talents. All of this I believe is necessary to hear what the leader of this fine company has intended thru proper design and engineering. It's all about extracting all its designed to do within your listening space. Time alignment is too powerful to ignore. My opinion based on tried and true experimentation with the YPAO systems.

Yes treating the room is important, but also use of existing Parametric assistance can't be argued either. If it doesn't sound better I will allow you to poke me in the eye and kick me in the junk!