With a bit of
research you will find dozens of A-frame mast systems. You might also find a few yard-queens in the less expensive
marinas all around. Were they anywhere close to the performance and ease of use
claimed, there would be more of them in the
water than sitting on sagging jack stands.
The issues, in descending order are weight aloft, windage, design and construction issues, and weirdness. The last is of course a plus to some observers.
The espoused advantages are a presumed disadvantage in the aerodynamics of a mast, the need to be headed into the
wind to reef, the need for a horizontal Guillotine otherwise called a boom, and the boring slavery of convention.
One of the most respected researchers in sail aerodynamics, Howard I Chapelle, is often quoted as saying that a mast reduces the
power of a sail by 30%. That is questionable, and does not address solutions like unstayed masts and rotating masts. Nor does it agree with the use of wing-sails in ultra high performance vessels. I suspect that were this number proven to be much lower, A lot of unsuccessful attempts might never have been attempted!
There is still some appeal in the
concept, (in my case where it would reduce the weight and complexity of the main bulkhead in a catamaran) if the problems of weight, windage and bare pole drag could be addressed. WW I fighters found advantage in streamlined struts. Airfoil shaped
aluminum extrusions were found on almost every aircraft built in the postwar Biplane era. I vote for a streamlined A-frame cross-section.
Tall, thin masts are held in column by multiple spreaders and a spiderweb of rod and wire diamond triangulations. They all sing in a brisk
wind. Where does the energy for the
music come from? Drag. I would vote for a very carefully engineered carbon fiber leg held rigid by internal webbing. If needed, it could be a bit fatter in the middle, and both legs should rotate.
Booms are a hazard. So are redheads and motorcycles. Live with it. They make to most common sailing task, tacking, SO much easier, and its nice that sails can fall into such an orderly pile on top of a boom. I vote to keep booms. A conveniently controlled
boom brake on the main and jib-boom would be icing on the hot dog. Yum. [an acquired taste, like catamarans.]
I don't like vertical furling sails on larger boats. They are heavy, require a
winch to furl making it painstakingly slow and incredibly dangerous as the wind whips the sail violently, inflicting injury to the crew or possibly a fatal blow to the
head by a barber-haul block left loose. You are reefing because the wind is picking up, right? A well trained main drops into a lazybag in seconds.
So, you may rightfully ask, if both legs rotate, what's happening at the top of the "A"? It's all loosy-goosey, right? And thats where you put a bunch of delicate stuff. How do you keep that orderly? I don't know. You figure it out and tell me. Inquiring minds want to know.....
Sure make a guy wish he had invested better LOL Love the idea of the all 
!!LOL just dreaming !!
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