Knowing something happens doesn’t mean that you care for it to happen.
The yad Yehuda doesn’t discuss this case Iirc, just explains the pshat in the shach
Getting back to the main topic (mods maybe remove cy/de fight to a different thread 🥱)
The Yad Yehuda (I looked it up inside) is not coming to say a kulah in the Shach rather IF it’s a case where most people would want it removed and he happened not to wash the pot it can be considered non intentional. In case of restaurant they obviously don’t mind the flavor and therefore it still stands that if it is done as a policy, you cannot apply such a heter. There’s no question that klapei fries this is true see up thread re tabernacle, no about the doughnuts there may still be a possibility, but again it is only going to be true if it’s not the normal way to use tainted oil.