[Dovecot] imapmagicplus equivalent?

Hi,

is anything like Cyrus IMAP's imapmagicplus option available for Dovecot? If not, would it be possible to implement as a plugin?

imapmagicplus: 0 Only list a restricted set of mailboxes via IMAP by using userid+namespace syntax as the authentication/authorization id. Using userid+ (with an empty namespace) will list only subscribed mailboxes.

It's a quite useful option for clients that don't understand subscriptions. E.g., I don't want to see all of my folders on my iPhone, by using userid+ I can limit them to a useful set.

Juergen