2D project with movement along Z and X?

By default 2D projects are set to move along the Y and X (at least that's how their collisions are constrained). I'm trying to make a top-down 2D game, and I understand that you can fake it by just rotating the 'floor' to face negative Z and move along X and Y. My problem is I have a complex pathing mechanic and building-setting functionality tailored to work on the floor grid, and would rather not have to rewrite the code to change this for something vertical.

Is there a way to either: flip Unity's Z and Y, or, better yet, get Unity's 2D collisions to be parallel to the ZX instead of YX>