Test completed. Here's what I did and what I got for results.
1 - Discharged 2s2p 6400 pack using ICE charger set for 10A discharge and 3.2v/cell cutoff. Due to the higher amps, the ICE actually cutoff properly, but the pack went back up to 6.8ish.
2 - Restarted discharge at 1A. ICE cutoff at 6.46v.
3 - Plugged the pack into MGM. MGM beeped an error; it was the error code that indicated incorrect cell count. I appears that the MGM needs a minimum voltage to register the lipos correctly.
4 - Plugged the pack into the BalancePro charger and charged at 7.5A for about 5 minutes.
5 - Plugged the pack back into the MGM. MGM started up correctly. Meter read 7.46 volts on the pack.
6 - Moved the throttle trim forward on my radio until it was moving the wheels and drawing from the pack at a steady rate of 2.5A.
7 - Set up a 12v CPU fan to keep things cool while I let them run for what turned out to be around 20 minutes. The 8-cell SPT nimh pack is powering the fan.
8 - MGM cut off the lipo pack at exactly 6.2 volts when running at a constant 2.5A. Assumedly it will cutoff the same at higher amp draws, but the pack voltage will rise slightly more after the higher amp load is cut.
Here's a pic of the point of cutoff:
I'm going to add another post that shows step-by-step exactly what I did with my radio to set up the MGM for 2s lipo.
All told, I'm happy with the MGM lipo cutoff. :)