There's a test you can run in tee time rounds to confirm higher rated players tend to depress rather than boost round ratings. I gathered this data yesterday for round 2. The columns are Score, Rating, Score, Rating, (# of players) posted after that number of MPO players had completed their rounds. You can see how the round rating for the same score continues to decline as the scores of higher and higher rated players progressively get added to the ratings calculation. I didn't track the FPO in the same way but you can see the lower rated FPO pool got higher ratings for the same score in this round, perhaps due to "tougher" weather conditions on average earlier in the day when they played.
MPO
64 974, 58 1020 (12)
64 972, 58 1019 (28)
64 971, 58 1018 (51)
64 969, 58 1016 (63)
64 963, 58 1011 (115)
FPO
64 968, 58* 1015 (60) *Catrina's score
Most players don't see this progressive ratings reduction because you have to take snapshots of the updated results every so often while you're playing. This ratings progression usually doesn't happen during round 1 because groups are mostly random skill levels other than the feature card going last. By round 2, the field has been roughly sorted into progressively higher rated cards. By round 3, the field has been sorted even more.