So I thought I'd try Split-grade printing, and I specifically chose my first trial to try and 'rescue' an extremely high-contrast negative.
It was one I shot on Rollei ATP1.1 before I developed at home, I just gave it to the lab who probably didn't appreciate that it was a "special" film that needed "special" processing. (well, fair enough, I didn't either at the time).

Anyway, so I tried the Les McLean method, at f/8 with a 75mm Fujinar high enough to enlarge 35mm to 8x10:
- did a test-strip at #0 at 2s intervals, got nothing to speak of in the highlights.
- another one at 5s intervals, started getting something at 30s
- did a straight test-strip at 35s, decent highlights but fairly black blacks already.
- did 30s at #0, then tried 1s intervals at #5. Pretty much anything above 2s was blacked out.
- took a gamble, did a test 3x5 at 25s #0 and 1s #5, didn't turn out too bad.

Then I did a full 8x10 with these numbers and it's not too bad, there's a cloud at the top that's totally white and a tree on the edge that's totally black, but there's still not as much detail in either highlights/shadows as I'd like (and I specifically wanted to try to get something better than what I could get with scanning, it's not much worse than the scan but it's not any better).

So, the question is, can I do any better? For now I don't think it's even worth split-grading, just a #0 will deliver more than enough contrast.
But can I get "less" than grade 0 using the colour head? Colours go up to 170, is there a CMY->grade conversion table? If I combine colour head *and* the ilford filter, will I get any better (ie less grade) than #0?

fwiw, here's the negative scan, it's the absolute best I can do with my v750 and Silverfast, completely reduced contrast, killed highlights and boosted shadows just enough before it started looking goopy.
The split-grade wet-print looks near enough to the same (just not as much detail in the cloud or the tree), but I'd like to get better if possible...