So what actual disabled people do is just to talk to the cashier, who will say “oh let me flag down one of the Noble Cart Lads” or “oh just leave it, we’ll have someone out in a couple minutes anyways”. It’s standard to have someone on staff that helps mobility impared (or otherwise disabled) people load their car. If a place has mobility scooters, they absolutely have one of these people too.
What you’re doing here is advocating for accommodation on a largely solved problem, without just asking the people you’re advocating for about the problem, and trying to signal your virtue while doing it. Stop it.
(The reason for no cart returns next to disabled spaces is that many people will just sorta fling their carts at the returns, creating a whole lot of obstacles right where you least want them.)