I've re-listened some studio bootleg material last weekend, and here is my tip for the companion material for the upcoming albums: Presence: Only fragments of some songs known (Tea for One, Royal Orleans), so here we'll get alternative/instrumental mixes (There is a blues cover song called Don't Start Me Talkin', but probably it won't be released).
ITTOD: Here we have a lot of alternative takes, and an unreleased song, plenty enough for a disc:
Carouselamra (take1, instr.) 10:55
Fool in the Rain (take1) 6:18 (count-in, alternative lyrics)
Hot Dog (raw version minus guitar solo) 3:22
I