I am currently in the process of designing an Isometric game, and one of the features we are trying to add, is using sprite depth maps to render geometry in the correct order.
The reason we are trying to do this, is a number of our game objects make use of overlapping sprites, and the animation is not always in sync with it's other parts.
I do have experience with working in 3D. But the issue comes to using something that is normally generated on the fly, pre baking it, and then retrofitting it to work with what ever distance.
So... something similar to what the sims has done with it's objects.