I also am having the same problem. I sent a feature request to Apple to support exporting .reality files in Xcode 26. https://developer.apple.com/forums/thread/787487

I would prefer adding exporting .reality files instead of bringing reality composer (original) to apple silicon because Reality Composer Pro has a lot more features and is more advanced than Reality Composer (original).

Yeah. Reality Composer Pro doesn't support exporting .reality files.

I accidentally closed the feedback assistant request. I made it again.

I am developing a world with complex cities and futuristic buildings. I have .usdz files, but since there are a lot of entities in the scene (maybe 20 or 30), I don't want to have to anchor all of the usdz files and keep track of them in code. Using Reality Composer Pro would be much easier. But I can't export to a .reality file. So I would have to use the original Reality Composer on iPad which is much slower for me, because I think computers are much easier to work on.