Is there a way to switch between pedal boards in modep with the keyboard?
It’s possible with a MIDI keyboard: MIDI Command Server 
For a regular keyboard, you can make use of the same scripts, to hook them up to the keyboard input.
It’s tricky though, as the keyboard by default is used by a login prompt.
Silly me. I meant a computer keyboard, like the one I am typing on.
Of course in this context “control modep with keyboard” means something different.
I have a foot pedal with three pedals that act like a USB keyboard with 3 keys and emits “a”, “b”, and “c”. I would like to use it with modep.
I can use it with guitarx, but that program is not as good IMO
It’s definitely possible, but it’s tricky.
If you know how to write software and how to configure Linux, you could make a program that listens to ‘a’, ‘b’ and ‘c’ inputs, and translates them to something usable by the ‘MIDI Command Server’ (or just look at its source code to make your own non-MIDI command server). Then set your system to boot to ‘console autologin’ target, have this process start by default (like via ~/.bashrc), and there you go.