From AI, whose advice is not 100% guaranteed...
"Crescendo can show a trill with either the ornament symbol (tr) or with explicit small “grace‑style” notes, but it does not automatically convert a trill symbol into reduced notes.
What Crescendo can do
- To add a trill symbol: select the main note, open its note menu (right‑click or radial menu), and choose the trill ornament from the ornament section.
- To add small reduced notes: place normal notes at the desired pitch, then right‑click each and mark them as grace note; Crescendo will display them as smaller notes (slash optional).
Workaround for “tr” as reduced notes
Since Crescendo does not have a feature that replaces “tr” with an automatic beamed group of small notes, the only way to show the trill as written‑out small notes is:
Omit the “tr” ornament on the main note (or leave it, if you want both indications visually).
Insert two (or more) grace notes before or after the main note (depending on your notation preference) and set their pitches to the principal and upper note of the trill.
If needed, adjust spacing manually so they visually read as the trill realization.
At the moment there is no built‑in option in Crescendo that links the trill symbol directly to a grace‑note‑style visual realization, so this manual grace‑note method is the practical workaround."