New Gym Prestige calculations already in place!!!
The scaling seems to be occurring when your trainer level as the Attacker is lower than the level of the Defender. Simply choosing a lower CP poke wont have an effect if your trainer level is above the defenders.
Was just training a friendly gym, battling a 1920 Slowbro with an 1800 Exeggutor and only receiving ~250 prestige per win. Then I used a 1600 Exeggutor and received the expected 500 prestiege per win. Seems the defending poke CP is already being adjusted in the prestige calcs.
The update is being rolled out and not a universal switch to the new calcs
Perharps will take 1 to 2 days to be roll out in Singapore
Source :
https://www.reddit.com/r/TheSilphRoad/comments/56t71j/new_gym_prestige_calculations_already_in_place/