I recently carried out some testing with HC110 and my jobo cpp2 with 4x5 fomapan 400 and using my XRite 811 densitometer. I took a series of exposures at various isos from 400 down and rotary processed them in my cpp2 using HC110 with a concentration of 1+30 for me that was 600 mls distilled water plus 20 mls of HC110, after fixing and drying I tested them on my densitometer and the negative that gave the correct density gave me a exposure ISO of 250, I then carried out some further development trials with film exposed at ISO250 and discovered that the best processing time for the highlights was 5 mins and 45 seconds on the rotary processor. This will now be my n development time for that film in HC110. I haven't got around to doing the n- or n+ timings yet but i believe you can approximate these with +/- 10% of the n time.