Ah, cool! I haven't ever used AudioStreamSynchronized, I think it's new in Godot 4.3. I'll have to take a look at that.
> As a side note, I tried to follow your tutorial on exporting to WebXR and it was all going well until the final step, which errored out because Godot couldn't open a specific zip file in the export template or something :(
Oh, no! Let me know if you want try and debug your problem. Just ping me on the Godot discord or rocketchat (I'm dsnopek in both places)