I understand that grace note deselection when changing rhythmic value was fixed in Dorico 4, and this holds true if I enter an explicit note length, however the note is still incorrectly deselected when changing the length with the shorten and lengthen commands.
Also if I select a grace note and press ‘R’ to repeat it, the note is placed at the beginning of the run of grace notes (this only happens when I’m not in note input mode, the note is correctly repeated in that case, but only if it’s created in that particular note input session. If I select a grace note, enter note input mode, then press R, the first note in the grace note run is repeated instead).