Hello Charles,
My mainsheet track is just forward of the main hatch and the sheet comes back to the starboard winch through a clutch like the halyards. We do not use the clutch when sailing but put about 4 turns of the sheet round the winch which holds it firm and it can be flicked off in gusts. In a gust the first let off is the track.
I also have an extra boom eye and deck eye on the cockpit floor for cockpit operation + tackle as I thought this would be better when short handed with the main sheet to hand for quick release or adjustment. In practice I had difficulty with the release and no longer use it.
Hope this helps. Trust you are enjoying the 285. The Isles of Scilly are great. We anchored off Mousehole for the night on the way out and back we stopped at the Helford River.
Clifford Miller P275 Abacus