If you've already got the commodities you need in the quantities you need then adding an extra station isn't necessary, but shouldn't have bad effects on your existing markets either.@Ian Doncaster SO I completed the refinery hub on the moon, and I now have all the refinery products at the Coriolis. Do I dare add anything else to the moon? I only have on slot left but I thought I might add a Civilian installation... Other than that, I was just going to add in the relay, government and security stations. I thought I might add a Coriolis or a commercial outpost around the moon but I'm not sure if I will now.
Depends how much Insulating Membrane/Tritium you're getting, I think - everything else is a fairly high bulk good - since that would benefit a lot from "strong link hub+planet" levels of economy rather than the 0.05 from a weak link. If you have enough of those for your needs then you maybe don't need another station.