My new Air Filter issue

[JOES31]

If it won't shut off 100% then the carb will leak even with the valve off. I would assume it would drain some fuel from the line because of the atmospheric vent on the bowl of the carb because the fuel in the line is above the bowl. Correct? Does the valve need to be shut down every time the car is parked? Is that what everyone does?

Without a filter and with most of the parking lots gravel and dirt years ago it probably did not pose a problem.