[evaneaston]

If you performed renames of songs and MobileSheetsPro couldn't match those songs up correctly during a sync, it means your two databases don't match. In that case, you really need to back up the library on one device using Settings->Backup and Restore->Backup Library, then restore that library on the other device (effectively wiping out the library and replacing it). If you do this, then the two libraries will match up perfectly even after renaming songs. It also ensures songs that are created from that point forward will have the same ID in the song table assuming you only add songs on one device at a time and sync in between changes.

I synced the two by syncing to a OneDrive folder from one then syncing from that OneDrive folder on the other.  Renaming on one device followed by a 2-way sync resulted in both the original and renamed song.  I'll try starting with the same backup and see what happens.  If that works, then I probably have no need to do anything with Song ID.