Yeah honestly, I think my original (somewhat unstated) goal of getting thrillingly high-definition 11x14 enlargements from 35mm negatives is probably just pushing the boundaries of the format a little too hard. At the very least, if I can't get it with Delta 100, a prime lens at its sweet spot, and Mytol, then I really ought to just be going to medium format or large format for prints of that size.
Looking at 8x10s (and smaller prints) I have made from 35mm negatives, I'm generally extremely happy with the acutance and overall appearance of my results, even with films like HP5+ that aren't resolution kings.
Pyrocat HDC has some other interesting features. I'm still interested in edge effects, and I'm very interested in the way the color of the staining might help tease out a bit more shadow separation. So when I test it, I'll be watching for those two things more than anything else.
BH, I don't think 11"x14" is pushing the boundaries of 35mm at all. I've spent the last 20 yrs working 90% with LF and MF, and recently coming back to more 35mm & that's my normal exhibition print size (for 35mm).....with pretty common lenses (nikkor, leitz,pentax et al)....it's not hard to get impressive prints at that size.
Although i love FP4+, TMax 100 has given me the sharpest (looking) results. I process most everything in Pyrocat. I recently printed an old negative (Leica 35mm Summicron) of Notre Dame before the fire. I didn't really think about it until the print dried....then i had to go back and see it was a Delta 100 commercially processed.
If i need more speed, TMax400 has been more than acceptably sharp. If i'm aiming for larger prints i still go to 120 or sheet film.
Don't look too closely, because this is an iphone photo of the print. But i absolutely feel that 11x14" is easily within the reach with 35mm. By comparison the 2nd (recent) photo (also an iphone photo of a print) is taken with a 50s Canon 28mm f2.8 (wide open) LTM on Tri-X and printed to 11x14". The image and tonality are higher on my priority list than "sharpness".....so much so that i sold off my (5x7") Sironar S lenses and went to Commercial Ekars and Dagors. Of course the rabbit hole you go down may/will be different than mine....
(*I wasn't doing much 35mm work and traded off my 50mm Apo-Rodagon... these were printed with a 50 Rodagon 2.8)