Trying to verify the idea of having multiple remotes to plug earphones into so each person can listen via their own earphones (which is a good idea for apartment buildings where noise complaints are frequent.
Will this work and how to initialize 2 or more remotes without having the ROKU Ultra box merely substitute one paired remote for another.
What is the procedure for pairing more than 1 remote?
You can pair multiple remotes to the same Roku device by going to Settings->Remotes & devices->Set up a new device, but I don't think they'll both be able to get private listening at the same time. I have no doubt that @Tivoburkee knows definitively.
This use case was discussed here a few months back. There is no simple straightforward way to have two people private listening.
About the best option is use mobile app on a phone/tablet which has headphone jack and use a cheap jack doubler.
The remote can't quite cope with a jack doubler.
Another option is to wire the remote into a small audio amp system that can offer a couple of headphone sockets "downstream", but that's a heavy clunky solution.
You can not use two remotes with headphones at the same time, never could not something they took away.