I do agree with this, but I also will say that I think we should represent atleast some of this transition by showing players why certain metabolisms don’t work in macroscopic (as in, still giving them the option to have these alternate diets but making it basically impossible to be based on them for long). There are reasons some diets just don’t last - for example, iron’s large scale disappearance as oxygen spreads throughout the oceans and surface. I think it wouldn’t be ideal if we just blocked out these diets.
Though I realize now after writing this that you aren’t necessarily saying “let’s block out alternative food sources” but instead the emphasis should be on the transition, which I agree with.
Some diets though I’m sure are basically outright infeasible in LAWK or Earth-like conditions. For example, I just can’t see a radiation diet working for macroscopic organisms. So that deserves focus in the discussion: how we deal with parts that almost easily go redundant in the transition.
Maybe one of Nick’s threads about nutrients/metabolism? Metabolic Rate System