As promised, below are FR plots showing:
1) 0dB/+3dB/+6dB Curves and
2) Flat/Natural/Aphile1/Aphile2 Curves
These were measured in a friend's 2.1 channel system - Martin Logan Prodigy mains (Big! dipole line source) + Velo DD-15 sub - measuring left channel only + sub. Although the room has been reasonably well-treated with various ASC and RealTraps products, there's no avoiding room response and others' results will certainly vary. Still, the general trends should be useful.
We also experimented with loading 0dB into position 1, calibrating, then +3dB into position 2, calibrating, and finally +6dB into position 3, calibrating, all with no reset. We had hoped that we might be able to "keep" all three curves by saving them into different positions. Unfortunately, it appears that, position aside, once you load a new curve via USB, all previous curves are overwritten.
Thanks to Sanjay and Ivan for their assistance, and to Greg, the long suffering owner, who put up with our shenanigans for many hours over a two day period.