Never had a problem with my Clubman bars, even with my Interstate tank. Might try tipping them a bit forward a bit to get them away from the tank and put the controls as far as possible out on the bars too. The controls were "close" on mine, indeed, no extra space for fat fingers etc, but didn't hit the tank. Try loosening up the tank mounts and making sure the tank is as far back on the frame as possible too.
I did get dents from clip-ons though, Dunstall was so smart as to put the hex head bolts on the inside nearest the tank. Couple good dings resulted. I run other clip-ons now, adjustable ones that you can adjust the tilt and wrist position as I got the old numb wrist thing from the Dunstalls. Clubmans did though, look the best of all of them, so try to find a solution other than butchering the steering stops. You need as sharp a turning radius as you can get, the Commando doesn't have as sharp a radius as other bikes I've tried. This was apparent when trying to get the bike turned in a close area.
OH!!!! I did wrap a nice thick cable tie around each stop and cut off the excess. They have been there for years and have never fallen off. One on each stop. Gave it a bit of a cushion so it didn't slam metal to metal at full steering lock...
If push comes to shove, trade the bars for a wider set...
