I would buy one. The J1772 protocol isn't that complicated.
I modified my granny charger or brick to charge with 240v power. The way I modified mine won't work with a GFCI any more as I ran the power to the control transformer on the ground, that way the control power transformer would only ever receive 120v power when plugged into 120 or 240v power. I figured that way I would violate every single "do not" warning.
Then put a 2m long cord on it. The weight of the brick was always trying to pull the plug out of the wall unless I set it on a stack of bricks. Yeah I know it's only supposed to have a 30cm cord and I don't care.
It's been like that since may or june 2018.