Look at the vid below between 2.39 and 3.00 minutes:
vid with camara on the rearbeam Mast feet just rests freely against the ball on the frontbeam in the direction of the hulls and is limited sideways by the trapeze-wires fixed temporary to both sides of the frontbeam. I use no step-hinges or things like that for anti-rotating the mast! Mast is fixed by the pole.
Only thing is you have to support the masttop a foot or so above the tramp. I use a simple tripod for that: the boom and two wooden side-legs.