I adjust mine all the time. I have a .22 that is set up for pellets (JTS 18.1s) and my "full power " setting is about 940 fps. I then dial it down as appropriate for the shot at hand - and if it is a chipmunk close to the house that could be as low as ~350 fps. I simply put a sharpie mark on the wheel, positioned so that it is pointing to the muzzle at "full power" and dial it back as appropriate. I know from testing how much each click drops it and the holdover required, and about 3/4 of a full turn clockwise (while looking at it, gun upside down) drops it under 500 fps.
It is so repeatable that I am simply amazed by it. I even tested it shooting groups where I alternated three pellets in the mag and shot each at a different power level, and all three pellets grouped very well down range.
As for having two different pellets in the mag, there is a member that had his mag laser etched with numbers for each slot - I've thought that if one had that done, they could easily put 10 of one and 9 of another in the mag and pick the one appropriate for the situation. But I find the power delta available from the power wheel is plenty on it's own, especially since I can load 25.4s and get back to 940 with those with a few extra clicks (and even 34s will do about 900, and that is regulated at only about 110 bar).
It is an amazing gun . . . .