Well it has worked perfectly well for me, let’s not complicate things and just enjoy sailing…so put the cleat on the deck?
Once upon a time, a sailor we both know well, decided to run the spinnaker boom down haul over a sheave up in to the mast, with a bungee cord up to the hounds. A much nicer solution compared to running it along the CB case, as most of us do, wouldn’t you agree? This sailor recently had to buy a new mast because it snapped at the hole he made for the sheave just above deck level. I am sure you can find his report somewhere on one of the W-web sites.
The area between the goose neck and the deck is where our masts are stressed the most. I would avoid drilling holes in that area. Below deck there is enough mast available to stick stuff to. The side of the tabernacle is another good spot to attach stuff to or, as you suggested, the deck.
A line that runs through a cheek block at the mast top is not only a nice topping lift but it doubles as a spare halyard as well. And thirdly you can use it to hoist the association’s pennant while sailing, or Christmas tree lights while night sailing on new years eve. These double functions is what most cruisers appreciate. But do carry a boom strut. A topping lift is only good to keep the boom up if you need to drop the main quickly. It prevents fouling the helm or, if you have one, the engine. As soon as the boat is ship shape we tend to put too much force on the main sheet to stabilise the boom. To avoid stressing the mast I prefer to put my boom strut in and release the topping lift as soon as circumstances allow.