For dealing with those pesky overages of atmosphere I present to you straight from the Spaceballs playbook:
Canned Air
This could be several tiers of building and the building would generate money from the sale of canned air at exorbitant prices to colonists.
The building(s) would of course use atmosphere because that's what's going in the can!
Trash would be used as well to make the cans and bottles the air is put into.
The building design would have to conform to strict Spaceballs building standards. In other words, it'd be a ball.
https://i.imgflip.com/10a87i.jpg
I would like it if you have to have storage for it. But if the storage is full, it can still be produced, but if you have more then 15m more then your storage,it will cause sickness
Its me Lego.
No storage needed, it produces money from the sale of the Canned Air to your colonists.
maybe make a new resource. one station that cans it, probably in aluminum say one aluminum and 100 units of air per can and so people with excess sell it to people who don't want to make atmosphere generators.