H.W.
On the Pelican we had a sort of gooseneck fitting to control the twist. On the KD 860 and the ECO 75 the mast rotates to control the twist. Yes there are also control lines to control the wishbone. This is in both version enough to control the twist in the sail. Because we use no Aluminum profile over the stay, the sail can be lowered like any normal main sail. In all the years we have had never a furler failure. I see no reason why the furler should jam. This problem from jamming mainsails is a problem when you have to roll the sail inside the mast. Then the mostly full cut main sail jams in the middle (because to much material form in this region) and yes, you have a problem. Multihulls have anyway less problems, because the corde to depth of a monohull main is normally 6 to 8 %, wheres 4 % is the maximum for fast multihulls. For a cover you can have a sleeve with a long zipper which you can set when the sail is furled.
Lucky you with a fast Internet. If there is some wind, and it is a region with much wind power failure is also a very common occurence here.?
Bernd