In solo mode, there should be a horizontally flipped version, such that such that the 0 key plays open E on the 1st string, and the 9 plays F on the 1st string, etc. That would allow me to hold my wireless keyboard backwards, facing the screen, rely on the muscle memory of my hands.

There was something like this that came with an old Sound Blaster card back in the day that I spent quite a lot of time with. It had something like this, where you could pick individual strings with the number pad and change chords with the F buttons.