Seems I didn't explain clean what I'm trying to achieve.

I have a domain, say, access.test.com. My users can use srv records to reach
it, or specify server's address directly as IP.
Default configuration with domain="all" works like a charm.

Then I moved from static files to xml_curl directory in database. Now every
time user registers I should respond with directory record, containing
domain in which user is trying to register, so I need to respond with IP if
user registers with IP, and with name if user registers with name. I do this
having DomainAlias table in my DB.

After user registration, I need to bridge calls to it by my routing rules.
But I don't know exactly how to instruct freeswitch to lookup user's
contact, since I don't know in which domain user is registered. I don't want
to interact with Freeswitch registration database, as it decreases
flexibility of solution.

At present I use force-register-domain set to my domain name, but I want to
use several names with different aliases, so looking for another solution =)