i think the italian bandini spar producer (or bimare itself) long time produced two part A-cat carbonmasts (with this idea behind to have soft and hard tops for different winds, crewweights etc...) they are said to had the undesired tendency to switch back to two-part mode when in use, either in strong winds or when capsized (actually I have seen this happening quite often when sailing A in Italy), very often also the lower part at the fitting to the upper part broke. besides that those masts seemed to have been never as competitive as for example a saarberg mast just made for your weight. so for competition sailing I think it will be hard to come up with a competitive two part mast. for more fun orientated sailors that might be a topic.

regarding shipping, when we imported our four taipans from australia to china the cost difference between a 20 and a 40 foot container really played not much a role...

if you can break it down to a length that you can transport it in a plane (hand luggage) than surely this might immideatly help to increase the amount of carbon fibre catamaran masts... ;-) oh yes, and just as the serious part of this feedback was finished already a sentence earlier, lets dream about kevin costners F60 featuring an impressive unfoldable power rig... just imagine... there comes light wind and you can enlarge your mast and sailsize 3 more metres... 1st of april? I admit, I am to early...