The problem is that when you want to use the storm jib it’s also the time you don't want to be going on the foredeck. Just when you really, really don't want to go up to the foredeck you have to, to set up your inner forestay and hank on your storm jib. Life, like the sea, can be cruel.
I suspect these inner forestay arrangements (particularly the more Heath Robinson versions) are rarely used. I bet most people just try to use a fully or almost fully rolled headsail rather than risk a trip forward.
Boats with small mains and big jibs are particularly disadvantaged because these large jibs are useless when rolled radically. A boat that relies less on a big foresail will already have a smaller jib on the roller furling gear so the furled set will be better.
I cruised for three years with hanked-on sails and then another three years with roller furling. If I were doing it again I'd seriously consider going back to hanked-on sails.
But that's a different discussion. If I did have roller furling I'd have a small, fairly heavy sail, the equivalent of a No.3 jib, perhaps, that would keep the boat sailing as the weather built and would set well even when rolled right down, and I’d change to this sail well ahead of the rough stuff arriving.
Big roller furling headsails are a nightmare when you get caught out.
