I assume 3D display refers to the Park Assist visualization.I think the parking map should not be in 3D display because:
1. It covers a big area the parking space we want to select. It's hard to select a spot in front of the ego.
2. It doesn't correctly show the shapes of the surrounding cars. A lot of times it shows the car behind my car as a grey football when I am moving out of the parking stall. I'd rather see it as a car.
3. 3D objects in my garage looks weird.
It doesn't do well with fully rendering and animating moving objects unfortunately, possibly a compute limitation. It also has a habit of showing pedestrians that don't exist; not sure why it struggles with that in Park Assist view but not the standard visualization. It does very well at giving a level of detail necessary for parking though. Hopefully the shortcoming will improve when they start optimizing for HW4. Might be helpful if you could switch between the 2 visualizations manually instead of automatically based on context, though I find it does a pretty good job of determining the right mode most of the time.