Good point on sled rotation. A simple gimbal may work, I’ll need to think on that. It may be easier to reverse the layout and put the sensors on the edge of the workspace.
The range is 2cm - 4m with an accuracy of +/- 3mm.
These sensors are only $4/USD each.
For about $15/USD each a triangulation infrared sensor could be used that would be a lot more accurate. Something like the Sharp GP2Y0A02YK0F although I couldn’t find variance info in the dataset.