Interesting formula, and will most likely try this out at some point. There's one detail, though, which I would like to clarify: Dequest 2010 aka Etidronic Acid is a powerful sequestering agent for all kinds of evil trace metals, PE mentioned this one himself, but it comes with some problems of its own:
if mixed into alkaline environment, it seems to do quite poorly with regular water hardness. It was the first "good sequestering agent" I got my hands on, and I tried to use it to avoid the slight cloudiness of my HCA. It did get rid of the slight cloudiness, but within a few hours I had white fluffy pieces of something floating in my HCA. Something precipitated, and it may be an insoluble compound formed from Calcium and Etidronic Acid.
The one photographic recipe I have seen, which uses Etidronic Acid, used a combination of EDTA and Etidronic Acid. There is also a patent, which recommends lithium salts in developers, and I have indeed seen C-41 CD formulas with Etidronic Acid as sequestrant and large amounts of some lithium salt.