

#1 is a terrible idea if you ever need to hire an electrician in the future, plan on selling your house, etc. The National Electric Code prohibits using white, green, or grey wire for a hot/load connection. The 120V cable will contain a black wire for the hot connection, white for neutral, and green for ground. To properly convert it to 240V you would need a cable that consists of black & red wires for the two 120V legs.
If your home ever suffered an electrical fire then this sort of jury rigging is precisely the sort of thing any competent insurance inspector would spot, and insurance carriers would deny coverage for since it clearly isn’t code compliant, which means a licensed electrician didn’t install it and it wasn’t properly inspected.
I have a nephew that worked at Tesla as a software engineer for a couple years (he left about a year ago). I gave him the VIN to my Tesla and the amount of data he shared with me was crazy. He warned me that one of my brake lights was regularly logging errors. If their telemetry includes that sort of information then clearly they are logging a LOT of data.