No, but I'm a mechanical engineer who's taken a subset of my uni's EE curriculum, done a fair amount of hobby electronics, read a lot about the SAE J1772 chargi

No, but I'm a mechanical engineer who's taken a subset of my uni's EE curriculum, done a fair amount of hobby electronics, read a lot about the SAE J1772 charging standard that applies here, and disassembled two commercial EVSEs (all in contemplation of building my own EVSE, which I haven't pulled the trigger on yet). It turns out that the engineers who designed J1772 thought a fair amount about how to handle the connect/disconnect concerns that you raise (via the pilot signals and proximity microswitch) and they didn't just leave it to EVSE designers to YOLO it. > I would want data sheets on the car/charging requirements, not measurements, to ensure this is true 100% of the time The "datasheet" that you want is the J1772 standard. There are many free summaries of it, including https://openev.freshdesk.com/support/solutions/articles/6000052074-basics-of-sae-j1772 https://openev.freshdesk.com/support/solutions/articles/6000... Scroll all the way to the bottom and read the section on "Proximity" to understand how the relays are not disconnected while large currents are flowing.