Looking for HVAC suggestions

I’m renting a mobile home without central HVAC and getting tired of my heater & AC fighting for supremacy.

Before I start, I don’t need to hear “that’s illegal in the UK”, or “Those heaters aren’t legal or safe” comments. They are legal in the US, and as long as I’m not bypassing any safety features, I’m completely legal.

I use an LG window AC with ThinQ, so I can control it via HA already. The issue is my heater, which is a ventless LP wall heater. The wall heater is 100% power-free. It has a basic manual bi-metal thermostat on it. I’m not looking to bypass ANY of the safety features of the LP valve on it, but need to be able to control it remotely and tie it into HA.

The valve in the heater has 2 gas outputs, pilot and main burner. The main burner line is what I’m thinking would be the easiest to control. If I put some sort of remotely controlled valve on that line, I would be able to turn the heater on & off, while keeping the pilot light going and without disabling anything on it.

Basically, set the manual thermostat on the heater itself to a level a little higher than I would normally run it at, the new valve in the main burner line would be opened and closed as needed through HA. I would need to build a controller for this, which would probably be an ESPHome powered D1-Mini using the thermostat addon. A new wall-mounted temperature sensor would be used as a single point for both the AC & heater, and I could also build a basic wall-controller with a display and temperature adjustment on it.

My biggest thing right now is finding the right electrically controlled valve for the main burner LP line. It’s ¼", so the size is standard. The problem I’m running into is finding a valve that can be powered 100% of the time. I need the heater to be able to run if the power goes out, so I definitely need a valve that would return to Open in the event of power loss. A solenoid valve isn’t rated for long durations of being energized. A rotating ball-valve would work, but I cannot find one that will return to open automatically.

If I have to, I can build the valve controller to monitor the AC power & a small battery. If the power goes out, the battery can be used to open the valve, then shut off.

Any suggestions?