Howto pin user in proxy/director <-> backend server setup

[Marc Roos]

I have 
1x proxy/director server 
2x backend mail server

The backend servers are using a ldap database and do not have the option 
to put a proxy=y value. So I put this as a default in the passdb option 
in the proxy/director config. When I do telnet localhost 110 on the 
proxy/director, I can authenticate with a test account on svr1.local

1. Will automatically all users be directed to the first server 
configured in director_mail_servers = svr1.local svr2.local, when the do 
not have a proxy=y or host=?

If this is the case maybe, we should write this somewhere on 
https://wiki2.dovecot.org/Director
https://doc.dovecot.org/configuration_manual/authentication/proxies/


2. If I change the host= in the ldap server, I think the proxy/director 
has archived the previous host and still redirects to the old value. Is 
there a way around this? (stopping/starting dovecot -F resolves this)


3. Do I need the director even in this setup?