autoexpunge wildcard mailbox from userdb

Was excited to see that wildcards are now possible on autoexpunge in the 2.2.24 release.

However I'm trying to configure these from the userdb lookup and it doesn't appear to be working.

if I set in 15-mailboxes.conf mailbox Trash/* { ... autoexpunge = 10m }

everything works..

however if I return

=namespace/inbox/mailbox/Trash/*/autoexpunge=10m

via userdb - it does not.

Logs say:

Debug: Unknown userdb setting: plugin/namespace/inbox/mailbox/Trash/*/autoexpunge=10m

Is what I am trying to do even possible?

Thanks

Leon