I don't like how Jpniewski's lines run through bullseye fairleads at the front of the hatch sliders. Especially since they turn the lines at almost 90º. Potential for lots more friction. I'd much rather have a deck organizer with sheaves. Problem is, there's just not much room for a deck organizer. Maybe could get away with one cheek block on either side, port for jib, starboard for main halyard.
The simplest way I've seen it done is especially nice on a Z-spars mast. The Z-spars mast was flat across the aft side. This allowed for 90º swiveling cam cleats to be mounted. The halyards can be pulled from back in the cockpit, or in the companionway. On a Dwyer mast, not so easy, because of the oval shape. Swivelers have to be mounted to the sides of the mast. It's how I did my spinnaker halyard. I don't have problems going forward to handle the main, because I'm there anyway pulling down the luff. But with the addition of a downhaul on my hank-on jib, I would really like to have another swiveling cam cleat for the jib halyard. Also, it would make it easier to tighten the jib as the luff stretches a bit with stronger wind, and starts to scallop some. Loosening the wrap on the horn cleat, just to pull maybe 1" of halyard when it's blowing is a PITA. The cam cleat would make this super easy.
Oooh, awesome, I have a picture of the swiveling cam cleat with me! You can see it here with the yellow spin halyard. Note how it's riveted to the side of the mast. I'd have to put a jib cleat below the horn cleat. Pay no attention to the ruler or the green main halyard, this pic was when I was measuring for a new main sail. I've seen a 192 with a Z-spars mast with 3 swiveling cam cleats on the back side, for 3 halyards, and it is a really sweet setup.