Rated 2 out of 5 stars
How exactly is this even a good idea? You're literally saying "when any webpage takes longer than this random number of seconds to load, something must be wrong and the solution is to interrupt the loading".
1) if you're targeting bulky Flash ads, it could very well be that the Flash is only a widget that's loaded instantly and then loads a stream from a server in its own process, avoiding the browser's meddling (like in the case of Flash video viewers).
2) networks and connections can be slow sometimes, making the page loading exceed the arbitrary number of seconds.
3) page loading time only (vaguely) indicates the size of the content, not whether or not that content is essential or unneeded
From the looks of it, literally the only purpose is to get rid of tabs that keep spinning for longer than x seconds, regardless of the cause, tab's contents, etc. How is that useful?