The R shortcut key can be used to repeat the highlighted note or chord in Write mode. When the caret is active, Dorico repeats what is highlighted (at the previous position) to the caret position.
Is it possible that, when the caret is active and I press a new note duration and hit R key, the highlighted note (or chord) is repeated with the new duration (at the caret position)? This would work in a similar way as Sibelius. I think this would greatly facilitate entering of chords for piano.