the OBD2 port is easily removable from the grey dashboard.
i did this for the extension cord, too.
so, you can push the OBD2 and move this plug.
i choose the extension cord because i must disconnect the OBD2 Reader.
i don't now if Kia Soul EV stop the 12v supply on the OBD2 plug when you leave the car.
perhaps, your black box device detect the none acceleration and stop to eat juice on the 12v supply.