Thanks for trying it! Yes, boundaryless was an issue; Godot provides a checkbox for boundaryless, which works, but Meta rejected the app and complained about the manifest when I tried to push a boundaryless version to the Meta Horizon Store. After the jam I made an issue in the Godot OpenXR Vendors plugin project about it and David Snopek helped me figure it out, he's already pushed a fix to master (thanks David!). And yeah, the room setup from within the game seems to be giving people problems - I guess I always had my room set up beforehand and didn't notice during the jam.
And no worries, thanks for trying it! Maybe I should have made a slider for the volume threshold to allow more people to try it without disturbing the peace. Ah well.