I'm just wrestling with shared folders and IMAP ACLs. These were introduced with 5.0.7 (see Bug #6937). I learned that setacl silently fixes the ACLs to fit to the three roles in Web UI, which was rather disappointing.
But my real problem is 'how to find all shared folders in an IMAP only environment'? A plain

LIST "" *

shows only the INBOX. A

7787 LIST "/home" "*"
7787 NO LIST failed: wildcards not permitted in username

If the folder is subscribed LSUB "/home" "*" shows it, but thats too late.

Any better way?