You can also put a cheek block (or two) on the mast, near the base and from there run the lines to your deck organizer. That way all the laods are shear loads and don't require big backing plates.
I agree with SD about running them to the cockpit. For the first few years I had my Garhauer vang rigged as you described with a cam cleat and it was such a PITA that I rarely adjusted it. Now that I've got it running to the cockpit, it's a completely different story. I knda wish I had the organizer capacity to run a few more lines back, i.e. cunningham, second reef line.