As I own the P12 module, which apparently has only few direct controls (knobs) for editing/tweaking, I made this layout to control every parameter from my iPad. First page is for oscillators, second for filters and amp. Then come Character/miscellaneous and aux envelopes and then one page each for LFOs, delays and modulation routings.
The next bank holds the same controls for the B layer (for splits or stacks). A third bank finally offers a few common things, the Arpeggiators for both layers and also the Reset To Default button, which sets all controls back to the same value as in the Basic Patch in the P12 (might take a while to complete).
For more convenience I added bank buttons at the top of each page, so I can quickly switch between the 2 layers and the common settings. Well, not always "quickly": it might take a few seconds to change, so be patient. There are some 550+ controls in this layout.
To make it work with the P12 you need to set it to MIDI channel 1 and set MIDI receive to "NRPN".
By the way the layout should work as well for the P12 keyboard.
EDIT: Made a little update (v1.2) with a few bug fixes. Namely the Amount controls in the modulation pages were showing wrong value ranges.