[Dovecot] lazy_expunge questions

I'm messing around with lazy expunge and I just had a couple of questions.

If I delete messages or folders with messages, I see them being moved to the expunge namespace, but if I delete an empty folder, all traces of it seem to disappear. Is there a way to move empty folders to the expunge namespace also?

My second question is in regards to restoring folders. If I try to execute the imap command 'RENAME EXPUNGED/TEST INBOX/TEST' I get 'NO [CANNOT] Can't rename mailboxes to/from expunge namespace'. Just wondering if this is possible or do I need to recreate the folder and then move messages into it.