Hmm, I was testing this out.  If you open a floating window and toggle its borders off, then it gets a little bigger every time you move it around, since xmonad still thinks it has a border.  Not that I see a good way around this.  What do people think?  Is it worth looking into this a bit more? Should we include the extension, but with a disclaimer at the top?  I don't particularly care all that much personally, since I have no desire to toggle the borders on individual windows.  But I know it's a feature many have asked for (specifically with floating windows).

-Brent