Thanks! You are so right. Also, a plastic zip tie to the bottom rail of the chain link will keep the HW butted up against the chain link. After posting, I saw the vulnerabilities -- and yeah, the "weights" are a bit tacky-- easily cured with staples. LOL - do you ever do something in an 'emergency situation' and know you will 'fix it' in just a bit, and before you know it 6-months have gone past?
I don't worry so much about "tacky" as long as it functions, but I could also see my dogs bumping some of those rocks while running around (they literally do circles around the run, chasing one another) and with enough bumps, the apron is now no longer doing anything.
At least staples are pretty easy to install. If time is an issue, I'd just nail in a few to get it tacked down on outer edges/corners, then go back later and reinforce when you have the time.
I use plastic zip ties as well but I don't like them in all applications. I try to use metal first (wire, o-rings, the lawn staples, even steel zip ties) on fencing over plastic zip ties. I mainly use plastic ones to secure my netting over the top (as that's for birds of prey) and any plastic ones on the fencing are intermixed with metal ones (due to cost and the fact that they aren't as easy to use).