Yeah, I also feel like creating an intermediary would be cool, but I’m afraid it would force us to add a lot more detail to Microbe Biomes which overall wouldn’t add much.
To now dabble in the topic of compounds briefly, something I wanted to mention is that we currently have the oxygen values misrepresented in the game. Oxygen does not effectively dissolve past a certain depth in the ocean.
At the surface, which for us would be the epipelagic, oxygen is basically equal to atmospheric levels. But as you go deeper it reduces. Colder waters hold more though, so the Atlantic has a greater amount.
In the table you can see that the ocean surface has high oxygen levels, but the overall ocean actually has quite low levels. We could use the values in this chart to help us rebalance the compounds in our biomes.
What would this mean in game? Oxygen is not common in the Hydrothermal Vents, Bathypelagic, or Mesopelagic, and would dis-incentivize the use of Metabolosomes in the early game (since it would be way less efficient). Therefore the first life will have to evolve chemical respiration or iron respiration, or chemosynthesis or thermosynthesis. Then, successful species that migrate closer to the ocean surface can evolve to use oxygen.
I got the figures from this source: https://rwu.pressbooks.pub/webboceanography/chapter/5-4-dissolved-gases-oxygen/