Overlay changes

Reviewers: @donovanhide, @ximinez, @rec
I hate the idea of just throwing away information that is useless 95% of the time, but can really save your bacon in the other 5%. How about logging at the lowest priority (trace?), and/or only on debug builds. If we're tracking down a problem, debugging and verbose logging are a typical first step, and may make a big difference in finding problems.