If OP is still intent in running the tests mentioned
in his other post, he should be reminded that there are few developers that are
just one developer. D-23 and D-76 do not give the same results at stock, 1:1 or 1:3 ; Rodinal is at least five developers, if you just count the main usages, 1:25, 1:50, 1:75, 1:100 normal development and 1:100 stand development ; Pyro developers are used at normal development, semi-stand development, stand development, extreme minimal agitation, as well as in different dilutions ; for some, such as HC-110, there is still debate whether different solutions yield different results or not, but if you are testing, you should at least try a few so you can figure that out.
Now, going through the list I've posted above (adding some I forgot, such as T-max developer, Perceptol and Ilfosol 3), if you want to be thorough and try all significant (or
possibly significant) variations of one developer, you'll end up with something between 30 and 40 "different" (or possibly different) developers.
Let's keep playing and say you want to test all main Ilford films — Pan F+, FP4+, HP5+, Delta 100, Delta 400, Delta 3200, and XP2 (leaving out Ortho and Kentmere for now) —, you end up with somewhere between 210 and 280 possible film/developer combinations. Add Kodak's Tri-X, T-Max 100, T-Max 400 and T-Max 3200, that's between 120 and 160 more, and you're up to somewhere between 330 and 440 combinations. And we haven't looked at Adox, Kentmere, Foma and others.
That also means that for each film, you have to shoot between 30 and 40 times the same scene in the same exact condition.
I don't know how much time you have on your hands, but supposing you can shoot
and develop between 10 and 20 films a week, that's still a lot of time devoted to your test project. Time
and money — even if you do half of it with just one film, say 15 developer variations with just Tri-X, that's still a lot of time and money.
Not saying you shouldn't. Honestly, if I were young, rich, and with a lot of time on my hands, I'd probably do it.
EDIT: thought about it, and no, would still rather go out and have fun with the camera.