My observations from flights STR-CDG last year (similiar for other routes like CDG-LHR, CDG-MUC, etc.):

- business/tempo challenge/tempo section is on most of the flights
*business: 2-2 seating, meal, pre-flight drink, hot towels (not always), lounge access
*tempo challenge: 3-3 seating, same (or at least similiar) meal as in business, lounge access
*tempo: 3-3 seating, snack and drink service

- two flights had only one cabin divider. The cabin was business/tempo. Both flights had huge (really huge) groups. The business section was large and it appeared that all full fare tickets and some status holders were upgraded in order to separate them from the group (noise).

- people with full fare tickets (Y or S) are seated in tempo challenge. Upgrades tempo to tempo challenge and tempo challenge to business are only done if necessary (= flight full and class overbooked). Highest priority for full fare passengers, then status holders. Upgrades are rare but do occur.