Don't worry about the gws esc and voltage cut off.
Most planes won't have enough power to remain airborne at 6.5 to 6 volts under load. So when the battery gets that low, you will be landing whether you want to or not...
I think the gws cut off is around 4.5-5 volts, and I think even that is probably a half volt off to the plus side...
The main thing you don't want to do is fly til the batteries are low, let them "rest" on the ground, then try and fly again before recharging. That will kill the Lipos by pulling them below 5 volts under load. Under load voltage is mainly what we're concerned about with lipos and r/c airplanes anyway. I mean, who sits around and attempts to draw these batteries below 6 volts no load anyway?