Shared mailbox name

[Kacper]

Hello,

Is it possible to have a custom name on a shared inbox?
Currently prefix = shared/%%u/ makes the shared inbox have the name of
the user whos sharing the inbox. I would like to set a custom name on
the shared inbox such as "My Recipes" (spaces included).

Background:
I've implemented shared inboxes by using groups in Active Directory.
Each group is a user with a mailbox and has it's mailbox shared using
a namespace. A post login script fetches all groups a user is member
of and includes them into the ACL_GROUPS environment variable.

namespace {
  type = shared
  separator = /
  prefix = Shared/%%u/
  location = maildir:/var/mail/maildir/%%u:INDEXPVT=/var/mail/maildir/shared/%u/%%u
  subscriptions = no
  list = children
}

I've tried using groups which contain spaces and mixing lower/upper
case letters.
"doveadm acl set -u "My Recipes" inbox group="My Recipes" create
expunge insert lookup read write write-deleted write-seen" works and
creates "/var/mail/maildir/My Recepies", but for some reason when
refreshing the imap subscriptions in Thunderbird dovecot creates
"/var/mail/maildir/my recepies" and  "/var/mail/maildir/myrecepies".

Thanks,
Kacper