Could you add an option in the settings to always display 5 string bass? I'm using a 5 string bass and, especially now that I reached level 5, I get confused a lot when moving between strings. Having the 5th string displayed would really help, even if it is not used, and it seems to be something that would be simple to do, as the app already supports 5 string on certain songs.
It would also be great to later enable playing of alternate tuning songs on 5 string without retuning, but really - just displaying the extra string would be awesome.