If you are buoy racing, you really only adjust it when you transition from upwind to downwind. Although our boats (Nacra 20 and Nacra F18) came factory rigged with the outboard rotator controls, we're going back to a boom system on the F18 for buoy racing. Usually the crew is inboard to hoist the spinnaker so the mast rotation, as long as it can easily and reliably be set during the transition, can be adjusted more quickly while they are inboard. We're rigging a 4:1 system inside the boom that has an indicator to show exactly where it is set (even if the sails aren't loaded up fully while turning downwind). It will take a little more practice to make certain it is set correctly, but it should work well.

On the Nacra 20, because the focus is distance racing, having the control outboard gives you a little more flexibility so it is staying outboard. It is being moved closer to the daggerboard so it can be accessed without having to go quite so far forward. Obviously it is important to get the mast rotation correct between upwind and downwind - it can be a bit of an adjustment while reaching and can be a good depowering tool when over powered (over rotating).