Grammartron (or something similar) for macOS

As a long time user of mp3tag in macOS via windows VMs or more recently crossover I would absolutely love to switch over to the native mac version of the app. The only thing stopping me from transitioning over is my inability to find (or knowhow to convert) one of the good title case scripts (such as grammartron found here: Case conversion...) over to native mac version, due to the different regex parser.

Any chance this has already been done, or at the very least some documentation that describes the diffs between the windows and mac versions of the regex parser?

You can find documentation about regular expressions in the Mac documentation:

That documentation indicates that the ICU regex engine is used in macOS, now I would need to know which regex engine is used in Windows so I could determine the diff and translate the script.

have you tried to run the actions on the Mac?

Yeah, the old Grammartron script does nothing on Mac. Unfortunately the regex in the script is fairly complicated and beyond my personal ability to parse.

From Mp3tag for Windows Documentation → Regular Expressions:

Mp3tag uses the Boost.Regex expression engine which has a Perl regular expression syntax. The Boost-Extended Format String Syntax is not enabled in Mp3tag.