To change a servers plaftorm multiplers, you can add the following into the UserGameSettings.ini in the [ServerSettings] section:
PerPlatformMaxStructuresMultiplier=1
The above: Defines the multiplicator for structures on saddle platforms (Please use with caution - too high values may lead to a massive lack of performance)
MaxPlatformSaddleStructureLimit=1
The above: Defines the maximum number of structures on top of the saddle platform