Teams - Resource account address book and information barriers

Hi all, we are starting to use Teams Telephony and have created some resource account for call queues. Initially the resource accounts were not showing up in the Teams search as we had the "Scope directory search using an Exchange address book policy" turned on in Teams settings (as resource account don't have a mailbox I assume they will never appear in the Gal).
If we turn that setting off, all the resource accounts appear, but so do a whole bunch of other accounts that we don't want the users to see (service accounts, emergency phones, display board service accounts etc).
To fix the problem we tried turning "Scope directory..." back on and using Information Barriers with two segments (one group with all the accounts we wanted hidden and another group that was not equal to the first group), but the resource accounts we do want to see are still not showing.
Does anyone know a solution for this?
Thanks in advance!
Ed.