I have done a small amount of work on macOS but it is not a priority. I did some preliminary work with this nice library:

https://github.com/gavv/libASPL

I have also thought some about whether or not I could make BlackHole work.

My takeaway so far is that macOS is more of a hassle for developing this stuff. It doesn't help that CoreAudio is not open source and the docs are hard to navigate. Hopefully someone will fix JACK-router on macOS one of these days.