The patch is in the patches folder
apt-get source budgie-desktop
Note. Upstream has made it clear previously that they do not support the global menu hence why the patch hasn’t been upstreamed.
So do keep your alt tab issue very separate.
As an aside what is the alt tab issue?
Additionally I see you have a script improving osx to linux usability. If your script had the ability to undo the changes then I would be happy to consider it as part of the Cupertino layout option.
BTW I am the debian and ubuntu budgie desktop maintainer