Save Copy In/ Delete Unused Regions - smaller sessions for mix

[Gee]

I would recommend you select the remove unused files before you "save copy in" (make sure its remove and not delete to be on the safe side)

once the original session is clean then do your save copy in

this has worked for me every time

if you hold down option and click on either remove or delete, you wont get the 1000 pop ups.

Good luck!