Wow, that's amazing stuff. Would you care to share your .offlineimaprc ?
I myself use the gmail source
(https://github.com/rakoo/sup/tree/gmail_source), but it's not very
smart at syncing old labels, and it's mostly targeted towards gmail, so
I'd like to switch to something else (plus having a local tree of
maildirs is always helpful)

-- 
Matthieu Rakotojaona