The prototype has been finished and the firmware is nearly done as well. All functions work as intended on Windows. I tested the device on IpadOS as well and weirdly, the keymapping seems to be wrong. This could also be a problem on OSX as well but I don’t have a Mac to test that with.
In short, the project is going very well and I’m ahead of schedule. I will be looking into PCB printing to create a more refined project.