well....
I weigh 225 lbs and spend a great deal of time reading in the hammock on the headstay without damaging it. However, I use my spinnaker tack strap, which is about six inches wide, rather than wrapping line around the sail. (My concern here is not damaging the foil, but the sail itself.) Much of the weight will be borne by the spinnaker halyard, not the forestay.The working load of your topping lift was probably at least 1,200 lbs when it was new. This as a conservative estimate because I don't know what type of line you have, how thick it is, or how old it is. You can easily test it by tieing a bowline in the end and jumping it--at your own risk--a few times. Please don't sue me if you blow out a knee, et cetera.I'd think that you're safer snoozing on the foredeck than over the cockpit. If something goes wrong, I'd rather land on a flat surface than smack my head on the binnacle or the companionway steps, whatever.I should add that I'm an English professor, not an engineer, and that all the above should be taken as well-intentioned advice of a fellow boat owner, based on one man's experience, rather than expert advice.