a way that you could add nitrogen without breaking olds saves too much would be to make clone and cray replace nitrogen with ln2 aswell as spawning it. the only problem is that the nitrogen would conduct heat.
i made a save using loxy to show what it would look like id:3390475
That would be cool, I turned loxy evaporating temperature into rflg instead of none, and the rflg sublimation temperature into loxy.