Is it possible to engrave something like the attached example in Dorico (litte notes which show the 2nd trill note) - it is actually from a Pierre Boulez piece.
There are workarounds
Also investigate adding parentheses to noteheads in the new Engrave > Notehead Sets dialog.
Auxiliary notes for trills are not part of Dorico’s current feature set, but they are certainly planned for the future.