So, you're sailing downwind with a goodish breeze blowing over your Stb quarter. Mainsail and headsail are both well out
when suddenly the need comes to gybe.
Now I know that as the stern comes through the breeze the boom is centered and then paid out as the wind takes it, but
what about the headsail. As you gybe and the headsail luffs is there a danger of it wrapping itself around the forestay ??.
Just how do you gybe a headsail ?.

I was following a small, maybe 25-28 ft, yacht up Pittwater some years ago. A fresh southerly blowing he was forced to gybe by another boat so was rushed. Got the main across but the headsail was flapping like crazy for some time as he sorted himself out. Before he got the heady in down came the mast at the spreaders. To make matters worse the boat that caused the gybe then crowded him while the drunk yobbos took pictures. Sometimes I'd like to have a rifle onboard.
Moral of the story, don't faff around with flapping sails in a fresh breeze.

Maybe just sheet on enough so the clew of the heady can't go f'ward of the forestay?

Large overlapping jib?

Yes sheet it on a bit prior to the gybe, and bringing it over quickly - quick hands pulling on, fast & tidy release. Helm can help here by steering a course to help keep the power out of the jib - But watch the main doesnt flick back!

Obviously this is not easy to do short handed, in which case the take home lesson can be dont run a full size jib in fresh breeze when sailing short handed ;-)