Please, we had this discussion many times. I am against putting this branch into our main repository. Two main reasons are:
1) it adds precompiled library binaries to repository, and we are against that (also, are these modified and are there sources of these?).
2) AFAIK it hacks SDL code into Allegro to make it run on mac, thus increasing general mess.
It makes it work and so serves its purpose, but it is not a clean way to do things.
Of course, separating OSX changes into a clean branch would make things easier to analyse. Also, so far it is the only up-to-date OSX version that actually works, so it would be silly to reject one. But I would suggest to keep this version in a separate repository for now until the issues I mentioned are resolved.
I also found my own suggestion made several months ago:
E: Since we now have an automation server, one of the options could be making a pull request that combines Janet's Humble Bundle port (not their pull request, but the most up-to-date version, I think this: https://github.com/JanetGilbert/ags/commits/humble-ports) and our current master.
The pull request will never be meant for actual merging (at least not until removing precompiled binaries), but it could serve for automatic building working OSX port.