I know the Platform Plus runs smoothly with S+(Same creator) as well as with Pillars Plus. Both should also cut down on lag by reducing the number of foundations/Pillars needed to make the various platforms work.
Castles, Keeps and Forts while absolutely AWESOME from a Castle-Obsessed-Nerd's perspective has had a hand in lag for past Ark servers. We had a base a fraction of the size of our Aberrant one and it was killing Raptors computer. Also seen issues with it and S+ on the same server causing superlag when accessing engram lists (Both add a LOT of new engrams to the game). That said, if we can get them to work together I'd be all for it. I want a castle! With dragons to roost on top of them.