It seems like the whole black smokers idea is not going to work. At least I don't see a way to do that. Here is why: we can't model all the fun stuff about them.
The bacteria that live near black smokers use the released H2S or plain sulfur (S) as a source of energy. They basically burn the stuff using oxygen. What comes out is sulfuric acid H2SO4. The concentration of acid is so high that sometimes it creates pH of 1. Maybe later we'll model the effect of acidity on bots, but for now we don't have that.
Then there is the issue of oxygen. The problem is that H2S will react with O2 on its own, without any bacteria. So the niche for bacteria is very narrow - the area that still has a lot of H2S but already has some free O2. We don't have a way to deal with gas pressures and chemical reactions within env. grid for now. So that has to go either.
So, what can we model? We can model a molecular source of energy that has a steep gradient. That's all. If you guys want that - it is very easy to add. But it is not going to differ much from being just another energy-rich molecule, except for a fancy name. Having a single unlimited source of glucose would give the same effect.
So I say we postpone the black smokers idea for a while, until we get effects of temperature, pH, and spontaneous chemical reactions incorporated into the program.
What do you think?