In my opinion it would be good (and help to speed workflow) two things in the multipass panel:
1- Add the "Multiple objects select" and "Multiple material select" like in Vray (sorry for the comparison): you select how many Obj or Mat ID you need and it create automatically them with a different name;
2- Possibility to select more than one voice contemporary (windows explorer style) pushing shift and left mouse button, so you can drag and drop all the selects into a folder or move them;