I'd be surprised if they did more than two as the pair of pyramids has been a thing since Divine Divinity. And from a gameplay perspective, several would seem to be overpowered unless they do something like restricting them to only transporting the character using the pyramid rather than the whole team.
I don't really feel that to be OP if we compare it with how teleport worked in DOS:EE. From anywhere you could go to any other portal.
Except to solve puzzles, I never used Pyramids. I guess I could have left one near my Crafting spot, ...
