Examples?

https://consentomatic.au.dk/

Pixel phones have been doing this for some time. I don’t think it has a relationship to battery passthrough. The phone will just switch to a slower charging speed at some point.

https://9to5google.com/2021/07/14/pixel-80-percent-battery-health-charging/

This kind of verification usually works by the user being visible on camera and holding their ID up to the camera, turning it in multiple directions to show its safety features.