I’d be up for expanded editions for all albums up to and including Abacab (at least). Including:
Original mix (which I don’t have).
Remastered edition of the remix (to try and breathe a bit more ‘air’/less compression into them?) or new remix.
All associated b-sides for singles released (and the A sides, if not on album).
Any material tried out but never used (not sure any exists, though).
Book with essays about the recording of the album (although much of this has been covered in the interviews in the green/blue/red CD box sets), plus lots of artwork/marketing and promo material, etc.
Yep, I’d buy those - hopefully on a regular release schedule (one every 6-9 months) - without blinking. My suspicion is that the box sets released before 2010 are felt to have most of the above already covered (or at least, there’s the view that they have, by the band itself).