Question in thread title…
Thanks.
NotePerformer performs only articulations that are implemented in Dorico. If my memory serves correct, those articulations haven’t been added to Dorico yet, but it’s something you for sure can expect to be added in the future.
If you explicitly write a trill (e.g. a series of notes with a slur) NotePerformer will perform it correctly. But I don’t believe Dorico generates a trill automatically from a trill line or symbol as for now. Please correct me if I’m wrong on this.
Arne is of course completely right.