Item 1:
I store the indexes and control in their own directory. I noticed in 1.1:
1192 ./private/indexes/.INBOX 32 ./private/indexes/.Trash 1228 ./private/indexes 4 ./private/control/.INBOX/.INBOX 84 ./private/control/.INBOX 4 ./private/control/.Trash/.Trash 12 ./private/control/.Trash 100 ./private/control 1332 ./private
.INBOX/.INBOX and .Trash/.Trash are both empty. This was an empty directory, I logged in with thunderbird and looked at the inbox and Trash folders.
Item 2:
I wanted to try imap_logout_format, forgetting what params it uses and taking a stab at it, but it seems to be ignored? It shows up in dovecot -n. I made it 'bbytes' just to see if the intentional typo would come through, but no:
imap_logout_format: bbytes=%i/%o username=%u
dovecot: IMAP(mcdouga9): Disconnected: Logged out bytes=439/169567