refrigerator size 400L autoclave cost 20K minimum. If you can use heating element to turn a container into extended autoclave => you are god of physics yo can sell this autoclave to me for 5K and mass sell to any one . Thermoeletric device you mean peltier effect? Its good for hobby mini size box, using peltiers to cool refridgerator sized container? you are mother of god of physics, You dont need to grow mushroom to make money just sell this cooling devices and you are rich.
I do agree with you, from technical point of view, its not rocket science neither some things special, I look at it from business point of view, trying keep some numbers in check, maximizing some and minimizing others. Some agritech start-up belly up because they forgot to keep numbers in check despite crazy tech .