Unbound DNS override for one client

[Gary7]

I block ad servers and tracking servers using Unbound.
I have an app on a Roku that needs to access a specific ad server or else if fails.
I can add an override for that specific ad server (or take that DNS entry out of my black list) and the Roku app works. Of course, that would apply to all clients.

Is it possible for Unbound to override a DNS entry for requests coming from a specific address.
Specifically, my Roku gets the real address and all other devices still get 0.0.0.0
Thanks.