On Busan - Downtown, there is a location accessible only on one side of the map. There are boxes that you can clip through and shoot out of while not being able to shoot into. I can’t seem to post links so I’ll try to describe it best I can.
Following the main road out of the spawn on the side with the cow balloon, right before you enter the main area of the map (where the cobblestone road ends), there is a highground with a generator/ AC unit on top. As genji, get on that highground and walk to the ledge that faces into the main area and climb up the glass wall on the left. You should be able to get to the top of that building. It overlooks all of the main-middle area, most of the point, and you can almost see a bit of the enemy spawn door.