I'm not sure I want to get involved in this sail folding discussion but I just recently (April) took part in a basic Keelboat sailing course on San Francisco Bay conducted by OCSC from the Berkeley Marina in J-24's and we were taught to both fold and roll. After removing hanks, the jib is first flaked out on the foredeck, folded to approx.width of sail bag and then rolledforward toward the tack. The main sail, when remaining on the boom, is carefully folded into perhaps 12" to 16" folds and then wrapped to the boom with ties and then covered. You would not be able to stuff or cram a sail with stiff battens or wire luff into a bag.
My HANDBOOK OF SAILING by Bob Bond advises that jibs be rolled if they have a wire luff and mains be folded, first from foot to head and then clew to tack to dimensions of sail bag.
But under stress, wedging oneself in the bow pulpit and being inundated with spray and breaking waves, anything may go when attempting jib change just to get it out of the way, including just dragging it still sopping wet into the cabin or an available locker. Whatever works under the conditions.

If anyone is interested in taking part in a first in a first class sailing course I would first recommend San Francisco Bay and then OCSC. Sailing conditions fantastic, facilities and boats top notch and instruction very intensive and most important, professional.

Bill K. M-17 #55