This should not be a problem at all. When my pax get in my car I always just start the ride right away and if they did input the address just confirm that it's the correct address and click on the navigate button. With the latest update you can choose between Uber navigation, Waze, or Google which makes it even easier. I've never had anybody complain about starting the trip as soon as they get in the car. Also if you get to their pickup location and they make you wait for several minutes remember that you are not getting compensated for that wait time. So like I said this shouldn't be a problem at all. These pax need to learn that when they request an Uber they need to be outside and ready right away (not 5 minutes from the time they request).