twin groove furling foils

[osteoderm]

Flipping through a copy of the West Marine master Cataloge ('05), i noticed a bit in an "info box" citing one advantage of twin-grroove furling fouils being that you can use them to fly twin headsails (poled out wing-on-wing) for downwind work.
Years back, first encountering twin groooves, and not (then) being a racer savvy to their advantages changing sails, i had assumed that twin groooves existed for that sole purpose (flying twin headsails). Asking more experienced folks i knew, i was assured that doing so would be highly detrimental to the foil, the sail's luff tape, or both. While some racing foils (such as Harken's snap-on carbo-foil) are clearly not intended for this treatment, others (such as Profurl's burly round extrusions) seem shaped to accomodate it.
What's the real deal? May twin headsails be flown from a double-groove furling foil without damage or serious hassles? Note: i'm definately not questioning whether twin headsails should be actually rolled up together; that sounds like a definate recipe for damaging chafe.

[Brian Duff]

I'll say that we have flown twin headsails from a furlex furler without problem,.
I can understand that the luff tape comming out of the extrusion at 90* angle to both sides could increase chafe and bending loads to the aluminum and in high winds could in theory cause trouble, we did not expirience any in moderate conditions.

[Brion Toss]

Hello,
As Brian notes, it is possible to wing-and-wing stays'ls in twin-groove foils, but heavy use will harm the sail. And in any event there are better sail choices for running; drifters, assymetricals, that sort of thing are lighter, better-shaped, and easier to handle. And twin running sails are notorious for generating "death rolls". So I'd reserve the twin feature for what it's best at: quick sail changes.
Fair leads,
Brion Toss