Even Tesla does it. This was last true in 2016, when you could add a dual-charger option to your S or X to increase non-Supercharger charging from 48 amps to 7

Even Tesla does it. This was last true in 2016, when you could add a dual-charger option to your S or X to increase non-Supercharger charging from 48 amps to 72 amps (dual != double because of battery limitations). Would you mind citing your source?