Did some experiments with the mesh z-elevation possibilities for doing a slightly angled viewpoint. You can make 3D shapes that are just one object and uses z-elevation while "faking" the vanishing point in a pretty simple manner. It requires a bit of set up, but it's not that bad (you basically "fold" the walls down from the top side by setting up the mesh points at the start of the level). Using 3D to distort meshes also don't cause the "funky" textures you get from normal mesh distortion!
Unfortunately there are some issues: There's no z-sorting for the mesh points, so if you rotate a box some walls are drawn in front of the top/each other. There's also tiny gaps where the walls meet (could probably be worked around). A much better option would be a customizable vanishing point for 3D objects though (wink wink, nudge nudge).
Here's the project I used for experimenting: Move around with arrow keys in the example.
dropbox.com/s/mh5oi1hgo70tubx/boxdemo.c3p