Beyond the percent sign used for repeating the measures, the slash mark is also used to indicate that a note or group of notes must be repeated in the measure. However, in Dorico 2, the slash mark does not produce any effects in playback mode. It would be appropriate as for the repetition of the measures that also for the repetition of the notes functions the playback.
The slash does not always imply an exact repeat, so it would be difficult for Dorico to provide a playback. Some arrangers use slashed bars to indicate improvised drum or even instrumental solo parts. That is why allowing notes to be hidden behind the slashes (for playback) is a sensible solution.
In the new tutorial “How to Work With Rhythm Slashes in Dorico | Getting Started with Dorico 2” is explained how to do:
Just overslide a region already written with music and overwrite it with the function “Create slash region” from the side panel (ctrl+9 Repeat endings).
The result is the desired one, i.e. the written music is played but is overwritten by slash notation.
Exactly.