You mentioned the “note highway” like guitar hero 
. Guitar hero does light up notes which should not be picked but played by “hammer on” / “pull off” those are techniques specific to string instruments like guitars. On a guitar you also do things like sliding from note to note over the strings and have various ways to play harmonics to generate different pitches on the same frets. So for a true note highway for instruments, passing on the midi numbers is not enough data. You would show something like an harmonic / hammer on icon or slide bars etc.
It would be nice to have a common format (or perhaps just midi) to add the technique data in. I understand it’s possible to just program, but was curious if there is a common format for this that people are using already. I know rocksmith does it hidden away in xml stuffed into psarc and it’s a pain in the butt to try to get abandoned parsers from github to work on such things.
For rythm games and many more applications your plugin does looks perfect actually.