Guy at my club has a very similar system, although he attached the diamonds to the other side of the pivot point and has the tackle above the lever arm. Below the lever arm and on the front of the mast he has a single swivel cleat with a split line running through it. The mast will rotate towards you anyway so a single swivelcleat is enough. He say he adjusts it regulary but hardly ever during a race. Pretty much he sets it before the race start and after a few test legs and then runs with it during the race.

But it is yet another line running across the tramp. I decided against it personally because I wanted to keep the boat simple. But at one time this system was on my drawing board, as was the case with many other gadgets that went to the dustbin for reasons of cutting cost and complexity.

Wouter