Running 12.8.2 here and have no latency issues playing VI's from a midi keyboard(Motif es8). I'd start looking at other sources of latency(granted, I don't run UA Apollo and never track with UA plugins).
Re Keyscape being a hog, I totally agree, but it doesn't have latency here, it simply causes cpu spikes(and will stop playback). My solution is to record midi with MiniGrand or Lounge Lizard(Wurly or rhodes sounds) and once the midi performance is good, swap the VI plugin to Keyscape and use Track Commit
