Great extension, works really well in most cases, though I haven't figured out how to block those annoying elements that appear when hovering over elements on a page.

For example, on Reddit, when you (accidentally) hover over a username, I want to block the huge element that appears containing info from the user's profile, but when you hit CMD+Opt+B to select the element, the element disappears and won't come back until I exit the element block selector, so I can't block it.