What in a nutshell are the differences in the final effect on the negative when for example diluting D76 1:1 vs 1:3. Will there be gray range differences and contrast differences or does this only effect grain size and grain sharpness ?
Ultimately, I think you'll find that you be able to achieve the same gradation with the 1:3 dilution that you'll find with 1:1.
I used both dilutions in the past and I don't think there's any real beneift in using the 1:3 dilution. The difference in sharpness was not apparent at 7x but the increase in grain was perceptible.