Oops, sorry, I wasn't checking in on new threads.
If you ever pop in to see this, I guess it's possible to set that up with my incredibly limited knowledge of modding, but I'm hesitant to do it for a couple reasons.
1) I'm not 100% sure I can get it to work
2) I really wasn't looking to make this mod "mine" by reposting it. I did modify one feature already, so I guess that point is kinda moot, but that change feels like I'm taking a step further
3) I feel like the mod is already a bit OP as it is. It already makes stone mining almost pointless, and having it offer coal too would make new ways for it to be abused, like putting a pollution cleaner next to your plastic or grenade factories so you can skip running a coal line to them while also cleaning the pollution from those factories.
All that said, I will think about it, and offer it as a separate mod if I decide to do it. Or maybe make it a third, end-game building that is the same as the standard cleaner, but offer the coal too.