Could this be used with a check for Space Age being installed/owned instead of fully depending on it?
Some mods (Py, Mech Armor) use features from Space Age (either by copying the code or using Enable All Feature Flags) but are incompatible with the mod/expansion itself. I'd love to use this mod in order to see more SA stuff on Nauvis.

Any chance you'll add weather, or is it already in?

I'm not going to try to make Space Age content available to players that have not purchased it, certainly not by copying code out of the Space Age mod which is proprietary.

I apologize if I stated it an odd way: these mods (or the enabled features) still require ownership of Space Age.
From the Mech Armor page:
"Code and graphics copied mostly copied from space-age mod. Requires expansion purchase to function. Do not copy code or graphics to another mod unless that mod also requires expansion purchase. (It wouldn't function anyway because mech armor functionality ingame requires the 'space travel' feature flag to be enabled, which will only work if you've purchased Space Age)."

Enable All Feature Flags:
"TL;DR This lets pyanodons load for players who -do not own the dlc- and -are restricted from using certain features like freezing/spoil/elevated/etc-, but if they -do own the dlc- then it enables those optional integrations (in py's case, spoil/elevated/stacking/etc) without making a separate spaceage extension mod. This mod just serves to see "does the player own the dlc" and enable/disable features based on that, because of the limitation of declaring used feature-flags in info.json restricting players who don't own the dlc from loading the mod entirely; as well as no convenient way to check "does player own dlc" at runtime plus the additional feature of having a way to play with "pretend I don't own dlc"."