Who owns the wall box/charger? Is it Motability because they paid for it, or is you because it’s on your property?
“You” own the box, not Motability. I know they will only pay for 1 charger, for instance if you move home, you would be responsible for the full installation costs. similarly I know of instances where scheme members chose an electric car, changed their minds after the charger was installed and were permitted to keep it.