I would guess that’s because IIRC, there’s no official support for Emacs to display native windows in Cocoa, and Emacs is simply using macOS’ X11 compatibility system.
If you could fix that behavior so that Emacs behaves more like a native Cocoa application, I see no reason that the Emacs maintainers should reject a patch. Emacs has, as far as I can tell, always strived to use as much of a native system’s interface and conventions as possible. Emacs is very big, so it might seem to be a self-contained world of its own, but it’s trying not to be too idiosyncratic.
>I would guess that’s because IIRC, there’s no official support for Emacs to display native windows in Cocoa
You would guess wrong.
(If you install an X server, you can run Emacs on X11 on a Mac, but if you do, the text looks radically different from the text in other Mac apps. ADDED. whereas if you run Emacs directly on Cocoa, the way most Emacs users on Mac do it excepting the ones running Emacs inside a terminal environment, the text looks exactly the same as the text in, e.g., Textmate or Terminal.app.)
Hmm. I would then assume that Emacs has rudimentary rendering support in Cocoa, but is otherwise treating it as a variant of X11, and not the fully different graphical system it presumably is. Emacs still has no full-fledged Cocoa integration. That is still only available in the Aquamacs fork, as far as I know: http://aquamacs.org/
This is true. I hope I did not give a contrary impression? I was, somewhat briefly, aware of some of the complexities of Emacs running under NeXTSTEP (not the text-only Emacs 18 included with NeXTSTEP, but proper Emacs 19 with NeXTSTEP windowing support), but that was (obviously) many years ago, and I don’t claim to remember any of it. And I was certainly not involved in implementing any of it.
If you could fix that behavior so that Emacs behaves more like a native Cocoa application, I see no reason that the Emacs maintainers should reject a patch. Emacs has, as far as I can tell, always strived to use as much of a native system’s interface and conventions as possible. Emacs is very big, so it might seem to be a self-contained world of its own, but it’s trying not to be too idiosyncratic.