Thank you. This is a pretty cool feature that is just scratching the surface of a deep need, so keep at it.
Another perspective where this exact feature would be useful is in security review.
For example - there are many static security analyzers that look for patterns, and they're useful when you break a clearly predefined rule that is well known.
However, there are situations that static tools miss, but a highlight tool like this could help bring a reviewer's eyes to a high risk "area". I.e. scrutinize this code more because it deals with user input information and there is the chance of SQL injection here, etc.
I think that would be very useful as well.