I've got a TouchOSC template on deck for the KPA now. It exposes all of the functionality Kemper revealed in the NRPN doc mentioned above. Of course, this is pretty limited - Kemper makes no mention of SysEx to rename or store rigs, for instance.
The template is nothing fancy to look at - the KPA itself is relatively simple, so the layouts are pretty sparse. But I am pretty excited about being able to tweak the most common amp params (vol, gain, eq) and all of the effects in my chain on one page. The "Chain 1" and "Chain 2" screen caps tease this idea, although neither are quite complete. (I realized that a single chain including ABCD and MOD would be better for me. Also each the stomps need to incorporate their corresponding global controls - mix, etc. and for some distortions, EQ.) But the point is, you can have multiple Chain pages customized to suit your own needs.
The template is about 90% functional now. Anything with a red label has a known problem - pretty much all of the "type" and on/off switches are borked. And I have to circle back around and label values extensively. Effects are color-coordinated to correspond with the lights as documented in the Kemper Reference guide, and everything is as big as possible for ease of use. I've done some unconventional things, i.e. ganging Gain/ Volume and Treble/ Presence on XY pads. This is kind of an experiment, and I may reverse on one or both if it doesn't pay off.
I'll post the touchOSC file when this is a little more robust.
