I went to Islamabad Airport to drop off my mother- We were 3 people- Me, driver, Friend, co-pilot and mom, the one traveling.
Once you enter the Airport, you will see the Parchi walas before the security check- They charge 20 rupees per person who is not traveling, so I reckon that is a big turn off for most people.
You will be absolutely fine, just pay the extra fees per person.
At Lahore Airport- they will make sure that you step out of the car and wait, meanwhile only 1 person can go to drop someone off.
I am not sure why they have different rules for different airports.
At Karachi airport- 4 people came to drop my Mom off, the whole process was smooth.