Fun science/engineering project, but not very practical, as he implies. At least he points out the pitfalls/gotchas, especially the startup/shutdown connected full load concerns. That was my first thought before I even watched the video - this is gonna burn contacts in the J1772 plug and charger relays if not managed correctly.
If he really wanted to get geek about it, he could build and program a simple microprocessor board to emulate the vehicle and negotiate the load, just like the vehicle does. The standard is well documented.