Moving REH marks

Hi! I want to be able to decide positioning and also on top of which staves the REH Mark goes. Where do i do that?

ScreenHunter 206

You only can decide the type of instruments above which system objects (Rehearsal marks are system objects in Dorico) are positioned. It’s in Layout options>Staves and Systems>System objects.
Certainly some more granularity has already been asked before.