I responded to the fellow stating "The article says they sometimes play them slowly and speed the recording up to the correct speed afterwards." which implies a change to the time scale. But also if you do a "perfect" non-realtime offline rendering Black MIDI is pointless; a piano has 88 keys; if you want to play thousands of notes a second then the only "benefit" you get is either a comb filter effect when the same note is triggered nearly the same time or a 3 dB gain (on maximum) if triggered exactly at the same time; there are easier ways to achieve this, even in real-time.