Reduce gap between menu items?

Is it possible to reduce the gap (width) between Icons as show in the screenshot? I can reduce the height of the items and the gap between them but not the width???

Also... TLB uses the square icons/thumbnails, but as I see on the screenshot your images are not square, so you get the gaps in all cases.

Would be nice if the highlight width could be adjusted, but I can live with it for now. I look forward to the icon width option in the next version :-)

thanks