Re: It really latency problems, or is time sync problems?
Some people here don't want or get the idea, but it is entirely possible to write useful applications in JavaScript which are deployed over the web but which run entirely within the browser.
Make that leap and it's entirely logical that client-side JavaScript should be able to control MIDI devices. How else would you web-deploy a sequencer? (I dare say that it's possible somehow, and that someone has already done it.)
Client-side JavaScript apps are a thing. Sending back MIDI "telemetry" shouldn't be be. Could we concentrate on that?
-A.