I have a reefable boomless main on a C Class, the sail was built with a single reef point. I use a long pennant on the main halyard (no masthead ring lock) and a small pennant with a hook on the mainsheet to clear the bundled foot. If you are retrofitting an existing main it will need new tack and clew grommets with added cloth reinforcements and a line of grommets for sail ties. The mylar bundles up fine, the boat is much faster in 20+ with a reef rather than ragging the main.