Well that is certainly disappointing to learn. They should have saved themselves the trouble of a keyboard and just made a module.
It does seem odd. On my unit there’s also a huge deadband on the pitch bend wheel that makes it difficult to use expressively, and the aftertouch doesn’t start responding until some significant force on the keybed, regardless of the response set up in the mod mapping or envelope controls. And it’s marketed as a performance synth… I just don’t know. For now I’m just playing it over midi from a competent controller.