I hear you. I, too, would prefer if I could choose whichever app I wanted to be on top and whatever app I wanted to be on bottom, like I used to be able to do.
Having the background be the map (as Tesla is determined to make it now) instead of a solid color (as it used to be) is not a big deal to me, and I don't think it's really a step backwards. It could actually be a step forward for those rare times I do want three apps showing at once as I've never been able to do that before. Unfortunately, the way they've implemented it, it's not really possible in the configuration I'd prefer.
Camera on top, media on bottom is fine for me, when I want that configuration (the vast majority of the time)
The times I do want to use the map (not even NAV, just having they maps up so I can view traffic patterns), I'd like camera on top, map on bottom. But that's not possible as of now. As I mentioned, with the maps as the background and the a condensed media player, V9 does have the added feature of displaying 3 apps at once. Which is great, except is never use it because it doesn't allow me to keep the camera at top when the media player is condensed:
Allowing the camera to truly go to the top would negate that 3/8" difference in camera placement between v8 and v9 (currently used to display the street name while navigating) that Mark Z measured above. Allowing that plus a condensed media player at the bottom would open up the middle of screen for the maps/NAV in the background. I'd drive around with the camera on top, maps/NAV in the middle and condensed media at the bottom nearly 98% of the time if it were possible!
While .42 is a significant step forward from the original v9 release, I do hope and pray they continue to hear our complaints to improve this. I'm befuddled as to why Tesla is so determined to have the NAV occupy the top of the screen which is easiest for the driver to see when the dash screen also shows the NAV. I mean, I know it's done because the Model 3 only has one screen, but why market the two screens for the S and X as selling points if you're hellbent on having their UI's optimized for the single screen 3?