NTRG (NiTRogen Gas) could be put into TPT, *not affecting LN2*, if LN2 weren't made to evaporate into gas. NTRG could condense, but not the other way around. If, however, a developer wanted to make LN2 evaporate, a button or switch or something could be made allowing it (turned off by default)- even though another button would make the interface that more complex.