[Skip]

I have different tunings I use so I made the custom group 'tuning' and included the 'custom group' in the 'song title formatting'. These 'tunings are the same as using different instruments so I think the basics are already there. I do suggest there be more of these 'custom groups' to allow a bit more custumizing of the 'group tabs' and that they carry most if not all of the capabilities of the 'collections'/'setlist' groups. I would think this should be pretty easy to code also.
This allows me to see all of the 'tunings' [instruments] in the main song tab, using identical song titles. As a note I have 'let MSP manage my files', 'Create subdirectories for songs', and 'copy audio files' checked in 'settings>storage'.  
This setup gives me 5 versions of a song titled "Amazing Grace" and 3 of "Aura Lee", with the differences shown in the sub titles [I use 'key', 'tuning' and 'source' (for the arranger)].
Aura Lee
G DGA#d arranger 1
Aura Lee
D DAdd arranger 2
Aura Lee
D DAdd arranger 3