Thanks for the explanation. Unfotunately it doesn´t seem to be possible what I´m looking for....
Actually I´m using the Contour ShuttleXpress:
This has two Wheels, which I use for zooming and shifting, and 5 programmable knobs. As you explained, this also works via keyboard short-cuts which can be programmed to the knobs and wheels. I find it very helpful an use it also with other programs, but I would like to have more wheels to adjust Exposure, Contrast, Clarity etc. therefor the X-Touch mini is a great idea.
So Affinity needs to make an API or at least more short-cuts available....I hope that is on their to-do list...
Best Regards