When I worked at McDonald's in high school, the drive thru times were tracked (for manager shift bonuses) and the in store orders were not. Drive thru was always prioritized over in store if there was a possible wait on anything.

The only time management gave any priority to in store would be the case where a bus load of kids would show up before or after a school trip. That was just to get them out as quickly as possible before they can make a mess.