if so, sounds like a good push request to the main mod

Earendel already decided that this will not be a feature in main SE due to some planned use for pollution in space. So unless something changes, this won't be happening.
As for UPS savings, I don't think that pollution in space would really cause that much of an effect, considering that space tiles absorb it really fast.

what is the use case for the mod then? to mitigate an upcoming mechanic the base SE mod?

There were requests, and if you're using a mod which prevents evolution from scaling based on created pollution, then pollution in space is really pointless (until whatever new things comes around at least.)
I believe it'll be a part of CMO, actually. Or a similar mod.

Personally I didn't have much of it in space even before I made this, but I'm a weird person who used green modules up there. If you don't I guess it can increase the space surface map size, which can have some effects on the save size and stuff.