Hey great project! I am using a very similar system i implemented in NodeRed, but I have one main problems at the moment.
Sometimes the car does not respond. I am now debugging the issue and installing a WiFi AP closer to the car, but i’m not sure if coverage is the real problem or it’s the API that sometimes does not work. This is not great when another load is connected and i need to quickly reduce the charge rate to avoid exceeding the maximum available power. Is it something happening also in your use case?