No, for real. See here, GP approves. I know, you think that makes the case weaker, rather than stronger. But you're wrong, and I'll write more about that later.
Anyway, when was the last time you had to carry something and said, "Dang, I don't have the right straps/contraptions to carry this thing." Well, never again. And you know why I'm sure?
Because Ortlieb/Tubus says so, and make an add-on spring clamp for their new Cargo rack:
Topeak also makes an sturdy sprung rack that I like a lot, and it's inexpensive too. Here's a wee picture, but you can find it or order it at your local shop: