On other bikes I have a cargo net stashed around the rack as well. However, on B other considerations come in: 1. There is no good place for the net on B, particularly if you want no interference with fold. 2. The cords and hooks are already there and you do not want to pile excessive amounts of stuff on a folder, rather aiming for efficient multiuse. As to front luggage or rucksack, there is no point hauling it along if there is no expectation that you will be taking any load.
My anticipation was of a strategy of producing a net on the fly using the double cords and hooks, with the start along the post of
@alicat above. Given that the current B rack has already 3 hooks on each side, and my rack from a few years ago has just 2, the manufacturer must anticipate that customers use them. Some issue is that you may have hard time making it work when in a hurry and not training ahead. For illustration, with the envelope example I came up with what is below. I am only pondering whether I might be missing some more general strategy.
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