JC 2's solution.
I recently designed one of aluminium for my Hunter 25 and am having it made for next season. It'll hold about 6-8 eye straps for swivel blocks (depending on how many I want to put on it) and catch the downhaul and vang at the back end as well. It bolts to the SS tabernacle (mast step) fitting about 3 inches off the deck. I'm having it done in white Imron or Awlgrip (epoxy paint). I've already talked to Bly about having the HOW Chandelry carry this. If it works I will design ones for other boats. Look for it next spring. BTW I guess you know I will agree you are right on target-- your suggestion is exactly what's needed to convert '70s boats with halyard winches on the spar to more modern and user-friendly layouts. However remember there are MANY good reasons to terminate halyards at the mast. Singlehanding you will STILL have to go forward to gather in the sail and hank on the next one. Having the halyards led aft to the mast would therefore be a MAJOR hassle. Too much travelling over the length of the boat and you will ultimately get clumsy. I am going to rig the spinnaker and pole lift to be operated from in front of the mast (since that's where the work is done anyway). The rest of the stuff gets led aft, but with triple sheaves each side I can always change my mind. JC 2 H-25 Mk 1
