.. would be very handy.
note: Christoph, i assume the extension is rather end of life from your part so you'll eventually won't feel like stitching new features into it.. but maybe like so: i assume i could put that feature together, though: i haven't done anything FF addon related so far.. my main prob in this field is a dev setup.. being able to view the related console DOM, making changes to underlying JS/CSS without restarting the UA, and so forth..
If you could point me to some good resources on how to create such a setup (i googled.. seems a bit sketchy), i'd be happy to give it a shot..