If you are referring to the hole that sits at the very base of the mast, that hole is the drain hole for water that gets into the mast. I wonder if it is able to take the loads of a kicker. I also noticed the later 54’s do not have the same “hole-arrangement” at the underside of the boom as the early ones.
I do love your remark about the table behind the steering chair. I wondered the same thing. That thing must be the number 1 design flaw for the Amel 54. I actually removed it. That makes the cockpit much roomier as well. We now use a small foldable table if we need to support our drinks…
I was thinking about this thing to put against the back wall of the cockpit:
But maybe I will just change the way the original table is designed and make it a bit lighter as well.