Well, I thought I'd give it a try so I popped a pyrocat-hd developed 4x5 negative into my enlarger to make an 8x10 print (slightly smaller than 8x10 actually, due to the wicked curl in the paper...the easel blades had a hard time holding that paper down!). I'm using an Aristo VCLH and the EL Nikkor enlarging was set wide open at f/5.6. Had no idea what exposure time to give but knew that it would be quite long. So I gave 12 minutes. I stood there for 12 minutes. Anyway, I developed the print in MAS Amidol and it was almost perfect. I probably should expose for another stop...but I just didn't feel like standing there for 16 minutes, since my lens doesn't open up more. Maybe 16 minutes, maybe longer. I have no idea how this paper responds to such long exposure times due to reciprocity.
I switched to an HP5 negative that was developed in Xtol. It was thinner than the Pyrocat-HD negative, with a DR of about 1.30. I exposed it for 8 minutes at f/5.6 and it came out pretty good.
I guess the pyrocat-HD negatives block out more UV and perhaps that is why the exposure time was much longer?? At any rate, I think if I go this route, I will use conventionally developed film...or maybe I'll go back in my darkroom tomorrow and try that 16 minute exposure after all...
Maybe I'll post a scan later.