Looks like we are getting a new feature for the editor:
dagdp_xxx entites. (Dagor Dynamic Placement?)
Dirt road covered with bricks
Randomly placed mushrooms
Seems like you can add any RI from the RI list and cover a designated area.
Some funny stuff can be achieved:
Needs more research, but looks like you have to define the RI in assets to be used in the placer entity.