Is there any way to test async/await and actors on macOS 11? Some sort of runtime toolchain I can install on my dev machine? I've ported some code and would love to test it without upgrading my only dev machine to macOS 12 yet. Thanks! 🙏

I'm using Xcode 13, but the problem has happened since at least Xcode 11. I prefer a three-editor layout. Each editor equal width. This is easy to achieve: close all but one editor, then click the 'Add Editor' button twice. Each window is equal width. But EVERY time I close and relaunch my project, the editor windows resize. The middle editor will be 2/3 the size of the editor space, the editor on the left will be about 1/5th the width and the editor on the right will be a tiny sliver. So every time I open the project I have to close the editors, then re-add two editor windows to get them to equal size. Is there ANY way to have Xcode actually save the window and editor layouts between launches?