Curved mast is a bigger problem for
..for in-mast furling. From theoretical point of view , in boom furling is better , as it makes for better performance/mainsail shape(1. battens 2.roach 3.not flat shaped) , for better stability ( the CE moves directly down when reefing in strong wind , not maily forward) and for better safety ( if it get stucked , you should still be able to lower the sail).I hope the technical snags will be sorted out to enable in boom furling to become as popular as in-mast furling.20-30 years ago , a simple version of in-boom , was the only system available for small-medium sized boats , at least in Europe, but sufisticated newer sails and new-trendy-in-mast furling , brought this systems to a complete stop.