Jay: Because I'm looking for magic bullets here! In seriousness I made this post basically to make sure I'm not missing something important about Pyrocat. E.g. if everyone responded "Um yeah that's what TMX in Pyrocat looks like" or conversely "Dear lord you've read the directions wrong the actual dilution is '...'!" then I didn't want to throw good materials after bad chasing down what would be an obvious problem to someone more experienced. Re: contrast, this is a totally appropriate question but I lack a densitometer and don't have a good way to quantify.
I'm definitely interested in continuing to experiment after all I think I have about 470ml remaining of both my pyrocat solutions and a few more exposures of this magnificently composed still-life. I agree that overdevelopment is a possibility, perhaps trimming back to 12 minutes and trying again? I generally have been (many years ago now) happy with results from HC-110, but always looking for some little improvement where I can get it!
Andrew: good suggestions, I'll muck with these a bit on the digital side.
Ken: Thanks for the link, reading up now. And agreed on complexity, I was nervous making this post since as I wrote it up I was forced to reckon with all the glaring holes in my scientific method. I should spring for a densitomoter but it's a tough thing to spend money on. Of course I'll probably end up spending the cost in film and chemistry testing this to death....Reading!