Shouldn't be that difficult?

Given those are definitely available at exception time, because try() can access them in _trace, may be a matter of making some String indexOf in the displayed snippet with the available locals and then separating the line so the hover text can be added.

I think it could be quite useful. May try it if I have time.

Edit: Will require passing the Context to the snooper. Shouldn't be a problem. Maybe even just passing the exception to it and let it handle everything?