I am more than happy with what we have now.
What I would really love to see is a system with 5 (or 7) distances of walls instead of 3.
That would allow for a little bit more realistic movement. We'd need to have 5 or 7 frames for sprites, too. I'm pretty sure this will never happen, which I'm okay with. I am thinking about ways to give the illusion of side-walls extending all the way to the vanishing point. The mechanics aren't hard, it's just when and where to use it so that I don't mess things up.