PC developer for J&C 100 Pro

I'm making some tests with J&C 100 Pro and HP5 4x5 films exposed with clear sun and detailled shadows.
PC (phenidone/ascorbic acid) Gainer's developer is the first used without sulfite.
8,30 minutes with J&C 100 Pro and 10,30 minutes with HP5 are the starting times. Films are developed in plastic hangers, 8 sheets in tank, plastic too, with 30 seconds agitations and 10 seconds every minute.
Stop bath plain water and Suzuki fixer.
Results are good, but now I have made a batch of J&C 100 Pro and HP5 exposed in low contrast in a wood with complete overcast sky.
There are some suggestions about developing times with Gainer's PC?
Someone have tested J&C 100 Pro with others developers?
With Pyrocat or PMK?
I will use the negatives to make small enlargments (8x10).
Thanks for your suggestions.
Daniele

I've only used commercial off the shelf developers with J&C Pro 100 - HC-110, Ilfosol-S, Rodinal, and Microdol-X. OK, I did do a couple of rolls with Folgernol, but I wasn't being very serious...

Anyway, my favorite combo thus far has been Microdol-X 1:3. I use 16.5 minutes @ 68F for roll film in a stainless steel inversion type tank, 10 sec aggitation at start, 3 inversions every minute.

I've only processed a few sheets of the 8X10, so take my comments with a grain of salt, but I found I got nice results with Rodinal 1:50 in a Unidrum (sorry, don't have my notes handy for the time used). I intend to try the 8X10 in Ilfosol-S 1:9 soon. I've found that Ilfosol-S does a nice job of taming contrast with J&C Classic 200 (a completely different film from a different source, I know...).