Here's what you do:
Work only with the palladium at first with your test strips, equal amounts FO and Pd.
Find your optimum exposure where at least 2-3 sections of the step wedge are pure black and indistinguishable from each other.
Then look at your highlight portion. Is it paper white? Or dull?
If dull, try just a drop of 2.5% NA2...a little goes a long way so take that into consideration if you're doing small test strips and not a print.
There's more, but that's all I have time for now...read the Arentz book...twice...and read it again.