What’s your chamber temp with bed fans like? I just mounted a chamber thermistor (on the floor, I don’t feel like running cables through the drag chain right now) that I need to connect but the little thermometer module on my gantry was reading like 58 ish at 100 c bed temp, dropped to 56 ish overnight, was getting 40s before moving them to the front and actually setting up the automation macro for them.

For impromptu insulation, Cardboard works well too, I stick my filament dryer in a box during the winter so it can actually hit the target temps, otherwise it runs forever.