On A&E's they have an optional anti-billow device that can be installed. I have them on both my slides covers. They must work as I've never had any trouble with them unfurling.
I've been searching for a link to it but haven't found one so far other than a small picture of in on the Camping World site.
On page 8 (HERE
) they show how to install it.
According to that I installed mine wrong! They say 12:00 o'clock and mine are at 1:00.
2009 45' Magna 630 w/Cummins ISX 650 HP/1950 Lbs Ft
Charter Good Sam Lifetime Member, FMCA, SKP
RV'ing since 1957, NRA Benefactor Life, towing '05 Odyssey