In relation to what we can track, element-wise, I’d like to see some test of the overheads; my recommendations (repeating an earlier exchange), based upon what we can handle computationally, would be:
15 elements: C, O, Na, Al, Si, Ca, Ti, Fe, Ni, Zn, Sr, Zr, Ba, La, Eu 10 elements: O, Na, Ca, Ti, Fe, Zn, Sr, Ba, La, Eu 8 elements: O, Na, Ca, Ti, Fe, Zn, Ba, Eu
Z is monitored already, and I would then simply derive He using empirical calibrations .. i.e., Delta(He)/Delta(Z)=2.1 +/- 0.4, and then H=1-He-Z .. gives the best breadth of nucleosynthetic production sites, to link in with observations. If one wanted to do some Cloudy-style post-processing, to look at ionised species in absorption/emission in the IGM, then maybe you would want to make sure to cover C, Mg, O, and Si, at least.