I just noticed that MusE doesn't recognize the automatable parameters of the Pianoteq 8 lv2 plugin. Not as audio controllers, nor as midi controllers. It does recognize the audio controllers of the vst version. They are recognized in QTractor, so it's not (solely) a Pianoteq issue.
All these parameters are automatable via midi cc by the way, so it's not really a big deal, but still..
edit: both MusE 4.1 appimage and master appimage.
The generic synth GUI MusE provides for the lv2: