As drawn, the travel exerted from the servo will be doubled using the ring, but the force available at the sail boom will be halved.
As the arrangement has to work in a range of conditions you have to figure that all runs must be free enough so that the slightest breeze will allow the line to pull out, but the line and the servo mountins must be strong enough to remain intact through a sudden gust.
Whatever is simplest is usually best - less to go wrong.