Tis better to be Safe than Sorry....
Not the greatest idea, I know because I have done just that. Rather than get a UV strip for each headsail I opted for a sumbrella sleave to cover which ever headsail I had on the furler at the time and I hoisted it up with a small diameter halyard. It works fine during season and is very convenient, but after checking on the boat a few times this winter it became apparent that the headsail and sock needed to come down. It created too much windage and I noticed that the cleavis pin holding the forestay turnbuckle to the bow was constantly working its' way out and I feared a failure so off it all came and it is now stored below. It is not that big a deal to switch sails with a Shaefer system that uses the external halyard, very much like hank-ons, only takes a few minutes and provides peace of mind. Every year there are a few headsails ripped to shreads in the marina I slip at and I don't want mine to be one of them, no sense in learning the hard way, it is simply easier to take it down. Don't listen to the naysayers who gamble and leave their headsails to chance, be safe and take it down.I'm surprised no one suggested a "sleeve" over the sail. Really, just a long tube of fabric, it is hoisted by another halyard so it encloses the rolled sail like a sheath.