I hoped v2.3.1 would fix it, but Scaler inserted as a MIDI Effect to Unify (standalone) v1.4.0 doesn’t seem to receive or output midi.
For example, when I press Record and play my keyboard so Scaler can detect a scale, I see midi in Unify’s MIDI Monitor just before the Scaler instance. But Scaler isn’t recognizing the midi. Also, if I select a scale in Scaler and use my mouse to play Em, there’s no midi output to the second MIDI Monitor in the signal path. Only when I bypass Scaler does midi pass thru.
I hope the attached screenshots make sense. Other MIDI Effect plugins work, although there are a couple third-party ones that seem to have the same issue. (Obelisk 1.1.6 AU, and Phrasebox 1.0.7 AU.) Running Big Sur 11.2.3.