The poles should add enough weight to keep the bag down. I kept mine in the bag the whole 13 years I had it and never had the bag flap around. An awning in a long fabric bag...it'll move around a little with out any weight. That being said, my Coleman awning had a header bar made (sewn) into it. That added weight as well. I know the awning w/bag had to weigh at least 20-30lbs. with the poles.
2013 Jayco Eagle 328 RLTS
2012 Ford F250 6.2L 4x4 CCSB W/Air Lift air bags
2002 Coleman Bayside Elite (traded)
Me, Momma and Charles (RIP buddy)
And introducing Sofie!! ;)