I wonder how hard it will be to release a floating cam cleat when the line is under a large load. Imagine you're sailing along in 10 knots of wind, it builds to 20 and you need to dump the main. Try pulling down on the cam cleat to release the load while it is flogging around or while it is taught but you pull down and the whole thing moves rather than releasing the sheet.

It won't take much to give it a try and would be easy to change back to the current setup if it doesn't work out. You could even try it out by tying a bit of line between the block and the deck fitting just to play around with it.

BTW, my main sheet is rigged to a block with a cam cleat on a traveler. The traveler is about 18" off the cockpit sole but even so I find it easier to put my foot on the sheet to release sometimes when there is a good load on it. That may be because I like sitting on the coaming which raises me up above the height of the traveler.