i just wish Jacks had Cobalt and Nickel otherwise id switch over to them 100%. also at least a little bit of NH4 would be nice.
Co, Ni, Cl, etc., are found as contaminants in fertilizer compounds and water source, thus they are not needed. That is, we shouldn't (or at least don't need to) try and add them, unless we are using reagent grade fertilizer compounds, which none of us are, nor are any companies.
FWIW, there has been an ongoing scientific debate about whether Co is 'good' for most plants ... I am on the side of "yes it is, but only in very, very low concentration, well below that of Na for example".