Bill has a great point: Don't make lots of little changes in one direction. Make big changes. If you're print isn't contrasty enough, make one that's too contrasty. Then you'll know better where the sweet spot in the middle is.
FWIW, I use a color head but don't bother with Ilford's speed-matched filtration combinations (it only dials in neutral density and makes many exposure times longer). Nor do I think about the grades. I just use yellow and magenta and find a setting that gives me a final print that works. I have no idea what grade I'm working with most of the time.
Having a proper proof to examine gives me a good idea for starting filtration. If you don't want to make proofs, a visual examination of the negative can give you an idea of its density range. Then, guesstimate a starting filtration, make a test strip and evaluate it. You can use one test strip to give you an idea of both proper exposure and if the contrast is close. If the contrast isn't right. Make a big change and make another test strip. Once you have narrowed things down a bit, make a straight print and go from there.
Remember, the first time you do an experiment, you don't learn about what you are testing; you learn about the experiment.
Best,
Doremus