Gothic, the short answer is don't do it.
Why do you want to leave your cooked food to decline in quality in the water?
Long answer is about determining just how harmful you want your food to be. It's probably best to create your own temperature gradient flow chart. You can calculate that by employing your knowledge of mathematics using the following variable details very time you cook using your smart plug:
- water temperature at the end of the cook,
- the combined mass of water and food,
- ambient temperature
- the heat loss rate of your cooking vessel.
Once you have completed that you can precisely determine when and for how long your food will be in the FDZ, Food Danger Zone, which is below 140F and above 40F. USDA Food Safety scientists have determined that 4 hours is the maximum cumulative time allowable for food to be in the FDZ.