Autonomous line

I wanted to know if any of you know the clarifications on the autonomous line. Is it that you can’t have a part of you robot touching the other side, or is it that you can’t have a part over the other side, but still in the air.
To simplify, could we have a line tracker that hovers over the autonomous line to stop us if a motor goes out and we can’t drive right.

The rules are quite explicit about it being contact with the tiles that is banned:

Your line tracker should be fine.