Spatial-backdrop standards process

Apple's WWDC video What’s new for the spatial web says the spatial-backdrop markup may change as it goes through the standards process (at 27:26 mark).

I have started adding spatial-backdrops to web pages, so I want to keep an eye out for status updates by Apple and follow the standards progress.

Is there any place I can keep an eye on this standards process?

Has Apple announced any feature updates or news on spatial-backdrops?

Spatial-backdrop standards process
 
 
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