For the roadmap - i'd suggest to slpit UI for multithreading first and fix all VST related bugs, i got 2 monitors and when console is opened in multidocking on second, then core1 gets overloaded and it produces sound errors.
VST bugs i've sent for a support, but if you'd like to change the forum, then maybe first thing you'd better change the online bugreport, so users could see similar bugs, test or prove it.
The arp fx bug is here in forum, that you can't add vst-arp as midi-fx, only mfx.
The other is about jbridge i guess, that it is reloading all patches sometimes when it should only change next and read only 1, instead it reloads all bank and then changes (occurs probably on auto-saving, can produce error).
And talking more about multithreading - is a thread control and balancing, usually each next vst loads first core, but if you move UI-thread to last core, then there will be more resources for vsts, since you can't change priorities of side-code. That's why i'd like to separate those for more threads, then if any threads goes into error it must not hang whole application, so if any vst hangs then for example a "reload vst" function can be called for any-not-responding or hand picked vst, just like we can stop and restart all sound on top. So this start/stop sound should be a separate thread and load/unload vst also as save/change-vst-state, because when playing live these functions can conflict (i think).
Really i'd suggest to use more videocard 3d-resources and GPU power for console (for example) and GUI in a whole, that will free up more CPU resources.
Sorry, maybe that's too much for suggestions and ideas... gl with that