Porcher is the parent company of BGF/Aerialite. Maybe your vendor can check the model # and let you know what the treatment is. I had to explain ‘Volan’ and ‘Silane’ to the local composites guy so I didn’t end up with ‘green’ glass when I wanted ‘clear’.
Yes 30" is plenty to get you a nice cut-lap or extra room if you’re the nervous type on free-laps. If you want those nice big fat old school 3—4" cut laps you’ll have to jump to 38" with substantially more waste. On free laps I typically use 27". I have gotten 1"—1 1/2" cut laps out of 27" on a longboard. It’s all about cost and waste. 30" is most common. Lowel
There used to be a worthwhile savings, in the past, by purchasing 60 inch wide cloth, and using an electric knife to cut the roll in half. It was routine, when I had Surf Systems and Surfboards Hawaii. Something else for you to consider.