Check out the cheap irons. I don’t know if they stii make one that doesn’t automatically shut off. I have a Black and Decker that I bought 15 or 20 years ago. It was the cheapest one sold at our local Walmart. Gets really hot and doesn’t shut off unless I turn it off. I have mine plugged into a surge protected power strip that sits on a desk top so I can easily see if it’s unplugged before I leave the room.
Rob