Something I stumbled on is if you home the bed before you heat soak with aux fan max it significantly improves the efficiency of getting heat into the chamber off of the bed. It increases the time to heat the bed by a large amount though. I have been able to reliably get to 60C which will keep the chamber in the 50s for the duration of a print.
I am planning to insulate the inside with Aluminized fiber glass insulation. I also plan to improve the air flow for the electronics and potentially insulate those from the heated chamber. I also bought a better fan for the nozzle to reduce the chance of thermal runaway from it not being able to keep up in a heated chamber environment.