I was just researching a similar solution for myself. What I am trying to accomplish is dual sound output; the TV speaker and a headphone, IEM or airpods. That way, we can both watch TV without blasting the TV speakers. My AirPods pair perfectly with the Apple TV and timing is accurate. But how can the TV sound still be on so she can listen?
I am considering a Bluetooth transmitter that has a toslink input and should not interfere w the TV speaker. And I think it has a 3.5mm out for a wired solution in case BT is delayed.
best solution would be to use my AirPods Pro’s and the TV speaker. I could use conversation mode so we could have a conversation while watching. Need to try and figure that one out.