You are missing the point I am trying to make.As for continuous versus separate. I lose a grand total of 3" length and associated flexibility. No biggee... I've trialed 14+ types of bungee, so I'm fully in control of exactly how much flex and strength I desire for my tanks. I've used 14mm,12mm, 8mm, 6mm, 4mm, doubled 4mm, doubled 3mm... you name it... flex and strength isn't why you choose a bungee method... It's why you choose a bungee material.
Bungee method is chosen for cylinder control, security and to suit your diving needs.
When you pull on the single bungee without tanks attached you have access to the full bungee length for stretching, less effort.
With one tank attached you can pull that close giving you an additional 3-5cm to use on the other side.
You can shorten the bungee a good 10 cm because of that and still have no problem attaching valves.