Thanks for the feedback, very helpful food for thought. Comments above in red.
When you use your own SS band clamps, what material do you use to protect the tank? The ubiquitous bicycle tire?
I don't use anything. When fitted, the bands do not damage the cylinder and they do not stay on the rental cylinders for long. They are tightened and they stay in place. I do use a short piece of dyneema tube to cover the screw assembly.