sorry for my late reply. That's a good suggestion. Also, the idea of switching to another mode via the Numlock key to simulate the Minimad keys could be very helpful.
For simple applications, a mouse would also be conceivable as an input device.
Right button for next medium and left button for previous medium. Or start / stop a sequence with the mouse buttons ...
(For simple interactive applications, you could convert an old computer mouse to an interface for door contacts or other switches)
For interactive applications, however, other minimad export options would also be helpful.
For each sequence: loop, black at the end, freeze frame at the end or automatic goto sequence x at the end.
If then still no black screen would appear when switching, it would be perfect. But now we are probably far away from the usb keypad ...