It's gonna be the fastest piano roll. It will have semi live performance kinda like Ableton live but live is sample based, mine is music based. I don't want to reveal too much, but I've talked to professional composers and kind of described the work flow I envision and they all were like "i need to this asap".
Idk if this will appease some of your concerns but I've been around hn for a while (I'm in the top 30 karma wise), I won't spam you.