Just to report back - setting the dials very finely, kind of by "feel" within the discrete values shown on screen, does seem to be worth the while.
I took some of my all-time favourite profiles - ones where I was happy I'd set the various parameters to the best values, and got the EQ just right - then saved new versions and "fine tweaked" every setting within the values selected. A/B-ing the results, it's not like the previous versions were terrible in comparison - but the "finely-tweaked" ones were noticeably a bit tighter, and even more spot-on EQ-wise. Probably not worth going to these lengths for profiles you're just experimenting with, but for ones you intend to use regularly, adds an extra "gloss", if you will.
Would be great if there was someway (e.g. in rig manager) to see the dialed in values in more resolution - just one more decimal place would do it!