We already had the Aussie Traveller anti-flap kit for our awning. They are absolutely fantastic. As
@Pace said, we use them every time the awning gets used. We did notice it sagged, just a little, in the middle, so we have recently put on some roof bars. We were planning on one but our service guy suggested two would be better. Our awning doesn't move at all now. We are very happy with the finished product.
We also have a full annex on our van, which we only use twice a year for a couple of weeks each time. I do enjoy the benefit of the extra room it provides during long stays. It also is great to store and secure the bikes at night time to prevent theft.