Is there any way to use RealityKit with Reality Composer in Swift Playgrounds (iPad)?

Any response from Apple?

Yes. Its now possible. I have written a proof-of-concept for pulling usdz & reality files directly from usdzshare.com to Playgrounds App on Ipad. You can just copy and paste the code directly into Playgrounds app & the Reality scene at this location will => https://usdzshare.com/?ug-gallery=photo-detail&photo_id=4148 will be imported straight into your Playground from the web. I'm also working on an api for custom queries. So you could upload your own usdz or reality files to usdzshare.com sharing platforum and build your own test apps in Playgrounds on Ipad.

Code here => https://usdzshare.com/reality-kit-in-playgrounds-app-on-ipad/

One option is to export to .reality, upload that to cloud storage and pull it in Swift Playgrounds. I've made a video to do exactly that: https://youtu.be/37o_Yt-wEJE Hope it helps!