Since Apple has deprecated opengl with Mojave there as been a lot of troubles. I think importing latest dev sdl2 would resolve the problem (and reverting back the displaylink commit for Mac vsync). I had a try but sdl2 is configured by default to dynamic linking and there is some hack to do to get it statically linked.
I had a small look and
Window and only has a few addition to
Window works (there is this vsync issue with previous systems). So it’s looks doable. May be posting an issue on github could be interresting if you really need it working.
There is this vsync issue with different Mac systems for now and I’d love to see it solved as well as those gl issue. But Apple is not helping here..