Some assorted gasses to tinker with

[Asterion0]

Void Gas could be cool as a sort of 'conversion' based gas that transforms the gas there's the least of into the gas there's the most of in whatever its in to facilitate making more of whatever gas you need without solely relying on mining getting the right rocks (and instead relying on telesci to have a void portal). Could also make the process of getting methane less annoying long term, as once you have enough you can 'industrialize' the production of it using void gas. Similar for Agent B where once you have enough to get off the ground, you switch to converting something less useful like N2 into it. Would probably need some limiter, potentially requiring very low temperatures to function (preventing it from being inside of a pipeburn), or consuming much more gas than what's produced, including the void gas itself.
Might be drastically unbalanced or incredibly difficult to implement (realistically both) but would easily add a new avenue for atmos involving the production of gasses instead of just using it up in a pipeburn, including recycling the various gasses produced by decayed plasma in nuclear reactors (I think this happens I don't mess with engine enough to know for 100%)