I frequently take the 6:30am MNL flight and you really do not need to be at the airport 2 hours ahead IMI.
If travelling in J/F one hour is enough. Sometimes immigration gets backed up (I've never seen it that bad at 6:00am) but so long as you have checked in 45 - 60 minutes before the flight the CX agents will yank you out of the security line and get you on the plane.
The airport and CX lunge at MNL are grim - one does not want to spend a great deal of time there....
No F cabin on the 6:30am flight