Thanks for your interest here, Quinn. Our interest lies in the fact that we have a third-party dependency that generates code for specific platforms. Up until recently that dependency was only building for x86_64 simulators alongside arm64 devices. With their recent update, they now produce an xcframework, which includes the simulator binaries for the platform on which it was built. They don't have an easy way (yet) to cross-complie and include both simulator platforms (x86_64 and arm64 iphonesimulator) alongside the arm64 iphoneos binary. We could invest in figuring this out, but with the signaling from Apple that Intel machines will disappear it is less than ideal investment of our time to figure it out.
At the moment we can use Xcode Cloud for archiving and submitting builds to TestFlight and the App Store, but not for running our unit test CI process for every pull request. We were hoping to move off our self-hosted GitHub Action runner to use Xcode Cloud exclusively, but until we can figure out the architecture issues for the simulator, we are stuck since our development machines are Apple Silicon.