Typing when you need it gives you more freedom over a toggle. You can choose to type some parts of the code while leaving other parts untyped.
For example, if I’m writing a quick and simple Python script I may forgo typing, but when iterating on it I’d go back and add the types I need.
At a certain point, layers will be pushed to RAM leading to incredibly slow inference. You don’t want to wait hours for the model to generate a single response.