dovecot - Jun 2019 - per-user mail_max_userip_connections in userdb extra fields

Hi,

The documentation at https://wiki.dovecot.org/UserDatabase/ExtraFields 
states that "It's possible to override settings from
dovecot.conf", as
well as the following:

 > If you want to override settings inside sections, you can separate 
the > section name and key with '/'. For example:
 >
 > namespace default {
 >   inbox = yes
 >   separator = .
 >   location = maildir:~/Maildir
 > }
 >
 > The separator setting can be overridden by returning 
namespace/default/separator=. extra field.

As such, we would expect for it to be possible to override 
mail_max_userip_connections under the "protocol imap" section, with a 
passwdfile userdb looking something like this:

 
example:{CRYPT}x:1011:1011::/mail/example::userdb_protocol/imap/mail_max_userip_connections=100

The userdb returns the expected fields in the correct format (according 
to the documentation):

# doveadm user -u example
userdb: example
   user      : example
   uid       : 1011
   gid       : 1011
   home      : /mail/example
   protocol/imap/mail_max_userip_connections: 100

However, this new setting is not honoured. To test, I set 
"mail_max_userip_connections=1" in 20-imap.conf, and noticed that my 
second connection was closed with the following error:

   dovecot[13573]: imap-login: Maximum number of connections from 
user+IP exceeded (mail_max_userip_connections=1)

I also attempted the same setting, without the "protocol/imap" prefix.

Is this not possible? Are there restrictions to what settings may be 
overridden in userdb? The documentation appears to suggest that there isn't.

Best regards,
Eirik Rye