The clamps you describe work very well. In consistently high wind conditions, such as Myrtle Beach, SC, I use two per side. The potential downside is that if you have to get your awning down in a big hurry it takes a couple of extra minutes to get the clamps off.
Happy Camping! ///// Richard D.
2006 4x4 Ford 250 SD / 2007 Flagstaff 827 FLS
One very patient wife and one furry child who travels with us. Forty-two years of trailering and camping, and I still have a blast.