Ah, yeah that's true. Mine is on a gpz500 so I needed the range. I know digital speedos do Daytona instruments and I believe the Rev range is right for the xbr.
The other thing is, do you need a tacho for the mot? I wouldn't have thought so.
Going back to the item you have, is there no way to "fool" it. Tell it your a two stroke or something! The Koso took a bit of head scratching to get it to read the right rpm. The instructions for wiring were good, but for actually setting the rpm the instructions were pathetic. Had to figure it out the hard way.
Anyway good luck and keep us informed.