It's unfortunate that the Chrome mixed content blocker fires before HTTPS Everywhere gets a chance to do rewrites. As a result, HTTPS Switch Planner won't show anything for the HTTPS version of sites like chat.stackoverflow.com. Hopefully this won't confuse site operators.

It might be very annoying in situations like this:
* https everywhere rewrites *.stackoverflow.com to HTTPS, including domains with mixed content
* stack overflow's site operator turns on Switch Planner and starts browsing around the site. He/she will end up missing most results because HTTPS Everywhere is (incorrectly) forcing HTTPS on stack overflow pages and the mixed content blocker has already blocked mixed content.