One useful feature would be to add footswitch settings / functions to the song parts. I presume it is possible now to add whatever sound you want the left switch to control within each song part but I think it would be useful to extend this section to include additional functions. For example I read elsewhere here of a useful request to move up and down between song parts rather than simply loop around in a forward direction each time. The footswitch buttons could be used for this, left for up right for down, and that functionality could be set with the song allowing other songs to have different footswitch functionality if you wished.
All this suggested functionality is currently being discussed, and will probably get implemented in future firmware versions.