0.10.5 was the last NWjs that works on MAC for me.
Everything else since is just the red bar load scene being stuck.
Even with all the attempted work-arounds, for some reason if your game has lots of assets/images, it will not work on MAC with NWjs.
The problem with 0.10.5 is a very nasty memory leak bug (which wasn't fixed until NW 0.13 builds!), in smaller games it's not so noticable, you have to play for an entire day to start seeing memory usage explode and the game stutters/crashes. Bigger games get to this point faster, ~30 minutes for my latest game.
That's why I went with NW 0.13 alpha7, as it fixed the memory leak bug, rendering is very smooth and performance is good.
But it's broken for GreenWorks support, and newer C2 builds will crash on NWjs older than the 0.13 betas (which are buggy).
Overall, not a good situation for PC export options for bigger games, and MAC is even worse.
Of all the things I love about C2, exporting builds to the different platforms has been the worse experience by far. If that's something C3 fixes, it would be the best 2D game engine around.