and ay there's the rub - neither of us are using Xcode, we're building from shell scripts. Making official MacOS builds from the source repository would have the same problem. Doing the equivalent work from the shell may be possible, but figuring that out may be beyond my ability.To build a macOS app that runs on both Intel and Apple silicon, create a universal binary in Xcode by including both the x86_64 and arm64 architectures in your app's executable and frameworks, then test on both platforms to ensure compatibility.
You may still need the MACOSX_DEPLOYMENT_TARGET thing to support Silicon Macs running MacOS versions older than what you built on. Would need to test that.