Hi!
Having come across some situation recently where this would be useful, I was wondering if it would become possible for the auxiliary note of a trill to be shown when the interval is a “Perfect 1st”. As it stands, when this interval is selected no auxiliary note is shown. Attaching some excerpts which demonstrate use of this.

@ViliRobert suggested a workaround using hidden tuplets and rests on a post on the Facebook group.