I just got my click-stand, and like it so far, although I haven't had a chance to try it out on varying outdoor surfaces yet.
They have a heavier duty click stand product called the "Click Stand Max" that's a heavier gauge. I'd call the guy who makes them and ask him your question, or send him an email.
His name is Tom Nostrant, and his contact info is on his website, but I'll paste it here as well.
www.click-stand.com/
berdeen, WA 98520
(360) 533-5646
info@click-stand.com
He's a retired school teacher, and when I called to place my order he was very helpful and patiently answered all my questions.
Ciao