We had a PPO BOG two weeks ago and it's advisable to get to MK by 7:30 AM. The PPO procedure as of two weeks ago was to check in to the left at the MK gates, after you tap in. The CM will scan your magic band to verify your ADR and give you a paper to show other CM's in the park (after they let you in). At around 7:55 they let us into the park and directed everyone with a BOG ADR to the right of the castle, toward where Merida meets. The path near Sleepy Hollow on the left of the castle is currently closed and blocked off. You check in again at BOG and go into the restaurant. I highly recommend pre ordering! You then confirm your preorder and make any changes, pay, and seat yourself.
I hope you can get an ADR for two extra people. With the way they handle the PPO reservations I can't see how they would allow the other two into the park to even try to get seated. The CMs at the gate scan magic bands to verify ADRs and the CMs seem to really watch everyone in the park PPO. They don't let people just "roam".
Good luck! Hopefully with some checking you can grab an ADR for two extra people.