Daniel, if I set the preference for articulations and rhythm dots after the note, I find that if I go pitch 6 T 6 . I get a crotchet tied to a minim. Dorico is dotting the whole value - a minim split over a barline - rather than dotting just the end section of the tie chain.
I think in real use I’d be resorting to Shift-Alt-Right in these sorts of situations, but I recognise I switched my thinking quite some years ago.