Exporting Apple Vision Pro, Final Cut Pro 11 MV-HVEC 10-bit 3D video to YouTube

I have shot a short promotional video for a high school theatrical production entirely on an Apple Vision Pro, cut it in FCP 11 as Spatial video, and it plays fine on our AVP. But I want to be able to share it for others to view on AVP or other 3D-capable headsets. I'm having a hard time figuring out how to transcode the video and inject proper metadata for YouTube sharing. Please help! I've tried Spatial Metadata GUI, Kandao XR, and other assorted HomeBrew remedies for this and gotten absolutely nowhere.