Alternating Tank (Custom Gas)
It would be great if tanks were "universal", I mean, not O2 Tanks and H2 Tanks, only... tanks. It would be great if tanks were custom and when you open the terminal you were able to chooce the gas that you want to storage in it.
Obviously (with mods) you can't store super-hot-magmatic-corrosive-acid-gas in a normal tank, you need one special. Gases could be categorized an tanks could have selected categories. For example, vanilla tanks could have only Vanilla tag (H2, O2), but a mod could have tanks capable of storage O2, Xe, H2O, but not H2, modders can make a "white list" of gases for their tanks.