And, if I understand correctly, it does allow devs to create “Master” plugins.
As for someone likely to use and implement it, I sense that there’s enough interest in microtuning, around here. For instance, from a post @Hussein, @binarysweets based Challenge #6 on microtuning.
No idea if any of these coders is able or willing to try something with MTS-ESP. Sounds somewhat likely.
(In the meantime, I’ll probably focus on existing implementations, including the VCV one. In the DAW world, I’ve been using Entonal Studio, which is proprietary and quite useful.)