I just got my Kemper Stage 12 days ago so this discussion is just what I needed. I just loaded my 1st profile 2 days ago and organization was not at all clear as far as what I wanted to do. I still haven't figured out how to re-arrange the rigs in the Rig slots.
I'm looking at this from a couple of angles. I have about 20 guitars, including mandolin, banjo, Pedal steel, Baritone, and Dobro. So I want the best rig for each, of course. I could set up 20 performances, 1 per instrument. Then, I have found that in my later years that I can make more money and do less work recording than I can playing , so I invested in my recording studio about 15 years ago. So from the studio angle I want to save the exact settings used to record. That's where the per song performance use works for me. If I want to punch-in/out I want the same exact tone. I can also keep profiles sorted by artist.
I am thinking that the backup/restore function will allow me to eat my cake and have it too. All that and I don't have to clutter up the Kemper . To that end I have a 128G USB drive dedicated to the Kemper Stage.