It would be great if Copy Down and Copy Across was available for the New UX. The interface can be a bit slow compared to entering data into classic modules so having this functionality may provide some improvement in this area.
100+% support for this! Even though it might seem like a small feature it is currently a gap between Classic UX and NUX that causes a LOT of pain for users who have to manually copy paste a value to a selection of hundreds of cells!