This app was mentioned in 3 comments, with an average of 0.67 upvotes
I wonder if LEA Extended Input Gamepad on a tablet would be useful?
There are other options for using a phone/tablet as a customizable controller. Maybe you can try them without investing any money.
One thing I do worry about is, if it requires a program on the PC, will it be detected as 'cheating' app? I don't know the answer to this one.
I use LEA Extended: Link to google play
I don't use keyboard at all, the best thing with LEA is once you have a profile you don't have to remember all keyboard shortcuts.
There's a better alternative to roccat
check out LEA https://www.leaextendedinput.com/
it can also use your old tablets and phones as extra control modules for ED or any game for that matter.