That sounds very strange
Round up and tiller are related? One has nothing to do with the other. A sailboat has a choice for steering, basically: tiller or wheel. The older C30s had tillers, then wheels were either added by POs or the factory started putting them in based on demand. Eventually they changed the cockpit layout to accommodate the wheels, but you'll find lots of wheels on the C30s with the old style cockpit layout.
A boat rounds up because it's too windy for the amount of sails that have been hoisted.
The answer? Reef. Which has absolutely nothing to do with the tiller or the wheel as a choice to steering mechanisms.