The opposite. The further a mono hull leans the more it will slip, so if you hike out and get the boat flat you will go faster and slip sideways less. In most dinghy classes slip is increasing from 10 degrees of lean - flat is fast as any serious racer will tell you. The sail foils will work better upright in most cases to, as there is more apparent area to the breeze. Centre plates, lee boards and keels work better as the boat goes faster - at rest they do very little and require a flow of water to provide resistance. This is why pointing too high or trying to get moving with the sails over sheeted (in too hard) in light conditions is so hard.