For 2 or 3 years now, whenever I have compared the two, the current version of "Mitsuharu" Emacs has always had fewer Cocoa-related bugs than the current (release) version of "FSF Emacs" (i.e., Emacs without the professor's patches applied). I am writing this comment because this Mitsuharu fellow seems very reticent about promoting his own (excellent) work.
https://github.com/Homebrew/homebrew/commits/a0b095b/Library...