"We need to be able to set up a perfectly flat canvas for a starting state to work with."
Orthographic view could do the work, no?
"We need a simple wedge option for top-down characters."
I don't understand wedge option. Clarify please.
Have you played "A Link Between Worlds"? They use a trick involving angles and the camera to make a 3D environment and characters all look the same as the earlier top-down 2D games. They make everything that's supposed to be upright lean sharply away from the camera. You get the full-frontal view of the characters atop a 3D world, just like the older games. I'd like it if we would be able to do a similar trick, and make a flat surface that protrudes further along the top edge than the bottom edge. Using "The Legend of Zelda" as an example again, looking at it top-down would still look the same, because the voxels are each a single color. However, the player can tilt the camera to get a more 3D view of the world, and the characters and enemies would still line up well with the camera.