@Sidetrack - it isn't trivial but I imagine not impossible. Like so many of these options most of the work comes in trying to figure out a UI for it without making a complex plugin even more incomprehensible! How well it might work depends on whether websites really do have a simple page=xxx type of querystring to manipulate, not all do.
I'll take a look at it "one day", but there are a whole bunch of other bigger changes that I'm part way through that I want to finish off and release first. And since we are fine tuning the Sigil release at the moment I've had no time to come back to this plugin, perhaps next week...