Doing something SwiftUI didn't think you were going to need. It's easier to force AppKit into super custom unique UI situations than to force SwiftUI to fit a UI it's not accommodating for. In some cases you will even need to drop back to AppKit to make it possible at all. Look back to earlier threads in this very forum and someone asked how to center a window on macOS programmatically, and the only real way to do it, at least at the time but I think still today, is to drop back to AppKit and get the NSWindow - SwiftUI has no way to manipulate the window object presently.
That's the catch