Mark I think it would be better and more practical if you make test strings of at least 3 exposures, box speed, minus 1 and plus one.

I'm lucky to have a hiQ camera body a Canon EOS 50e that let me do that automatically, makes test pictures from specific objetc, with sun (light here at this time of year, close to the polkar regions) against sun sidelighted open areas etc etc, I quickly burn a film with 5 separate triplets with space in the middle and repeat the same 5 subjects, cut the film in half and can test two developers under identical conditions.

I secured 4 films like that within 15 minutes just before Christmas, and still have films to go.

Doing it like that you test film-exposure-developer easier, and contrary to whats been said here, what interest us are PICTURES, not density curves, this is for practical experimenteres as far as I'm concerned, we are neither concerned with overly long storage capacities nor with hard to get chemicals....