Because the harp is not notated enharmonically correct, but according to the pedal positions, problems arise in the representation of trills.
A trill with a double diminished third (b-sharp/d-flat or e-sharp/g-flat) can Dorio not show.
If I have a trill b-sharp/d and in the next bar b-sharp/c I get this (please look tot he attached foto).
In the second bar Dorico doesn’t show the interval. Therefore it is not clear, what must be the target tone: the d from bar one, or the c, because it is a (diminished) second higher (like an ordinary trill).
Indeed, trills can’t have double diminished or double augmented intervals. As for diminished seconds, there is a bug that prevents displaying the auxiliary note of trills with diminished second interval, which will be fixed in the next version.
András, thank you for your answer! I hope that the possibility for trills with double diminished or double augmented intervals will be added soon. It’s indispensable for correct notation of the harp.
Until then you could notate the diminished second trill as a two-note, unmeasured tremolo.
Thank you very much for all the improvements also for harp in Dorico 3!
Unfortunately is attached example still unclear: The second trill need a little ‘c’ with natural as target note. This is apparently not possible.
Thank you Rob, now it works also for me. Perhaps I did something wrong.