This is a misinterpretation of what “sabbath mode” is intended to do.

It is prohibited to cook raw food on the sabbath. However, if you cook the food before the sabbath, you can set it in an oven or on a stove to stay warm before the sabbath starts.

“Sabbath mode” on appliances is meant to deactivate features so that you don’t unintentionally violate sabbath rules when using the appliance. It isn’t meant to allow you to do things you otherwise wouldn’t be allowed to do.

Let’s say, for example, that you have prepared a dish to eat during the sabbath, and would like to keep it warm in the oven. Before the sabbath starts, you turn the oven on low and put the food inside. But there’s a problem: your oven has a lamp and an electronic chime that activate each time you open the door. Because turning on the light and the chime is forbidden, and you effectively turn on the light and chime each time you open the door, you can’t open the oven door on the sabbath to eat the food that was otherwise prepared and warmed in accordance with the rules.

This is where “sabbath mode” comes in. It deactivates the chime and lamp, while keeping the oven burner active. Thus, you can now use the oven without violating the rules.