I've done CDG/PHL 4 times over the past 6 months. I aim for arrival 2 hours prior and usually have 30-45 minutes to use 1 of the 4 lounges that are in the same area for oneworld airlines. I travel J or PE with no checked bags.

The last 2 times, I received the dreaded SSSS on my boarding pass and needed to do the secondary inspection routine. If you are traveling J, you have the initial priority screening; if you travel in PE, you have the initial regular screening. Regular screening can easily take 45-60 minutes if you are in the morning queue. The secondary screening requires you to be "at the gate" 60minutes before departure time. They opened everything in my 2 carryon bags and did a very thorough search. They (CDG security staff) assured me that my selection was completely a random computer generated choice. I am lifetime platinum with Global Entry. My point in mentioning this is that, in J once and PE once, I still was selected. If you get SSSS on your boarding pass, tough luck for you. If you arrived later than 2 hours prior, you may have little or no lounge time, especially in coach.

The first warning sign of "winning" the security lottery is that you will not be able to generate a pre-printed or mobile boarding pass if you check in via computer or phone. Allow extra time if that happens.

The first time I "won" enhanced security, I arrived at the gate about 35 minutes prior to departure and just cleared the extra security before the gate "closed." The culprit was a bottle of "5-hour energy" in my briefcase, which I had forgotten about. This engendered an even more stringent source which uncovered a shampoo sample from the hotel. That are quite serious about security.

Everyone has their own comfort level with airport security. Mine suggests to me that I arrive 2 hours early.