Yesterday I sent in a LION patch to Plugin Alliance that adds in MTS-ESP and Apple Silicon support. Should be out in early May.
The MTS-ESP implementation is probably the easiest third-party library I’ve ever dealt with. It took less than fifteen minutes to add, and worked on the first compile. I’m pretty smitten with it. I spent way too much time hacking JUCE to get MPE and microtuning to play together nicely. On the plus side, they used LION in their demo video to show how nicely non-native MTS-ESP synths can interact with MTS-ESP, so that helped justify my time 
Anyway, I hope this shows up everywhere. I’ve been having a blast with it.