Is ARKit Body Tracking supported or is some sort of depth mask such as Hand Green Screening available?
No, you can find the supported ARKit features for visionOS here
We’re exposing the upper limb visibility property in future releases which I think is what you want.
barring this can you include something similar to hololens2 MRTK hand prefabs?
can you describe what functionality you’re looking for from these prefabs? I also recommend submitting an idea to the roadmap.
MRTK hand prefabs perfectly skin the user’s hands and can be use as depth mask for masking