A truly epic thread and Herculean effort to clean a cooling system. All I can say is - DAYUM!
jfirstford, I recall in another thread somewhere (maybe here, maybe the .org) where somebody had repeated oil cooler failures and the radiator was the culprit. Had it flushed at a radiator shop and piles of dandruff came out of it. It's worth a try, even though with all the Restore you have used it should be pretty clean.
Also, could your repeated clogs be due to the tap water flushes rusting the block?

 

I also rigged a kit to isolate and flush the radiator. It doesn't power flush it but I'm confident that I've removed practically all of the offending radiator dandruff (scale, brown flakes, fish food, or whatever endearing term you like for this stuff). My rad has been pretty clean since last Spring.

The rust was already there. Back in '07 my truck started leaking coolant and I was unfortunate enough to be dealing with an incompetent and deceitful dealership at the time whom would give me the run around instead of fixing the problem. I finally found a dealership in '09 that addressed the leaking oil/egr cooler hose, replaced my oil cooler, etc, etc... In the mean time I was topping off with the ole green stuff. I have to admit my ignorance of Ford's exclusive magical gold stuff at the time. This combination of my ignorance and trusting a sketchy dealership for too long back then is probably when the rust happened. I hate to admit my former ignorance, but you can never fix a problem without first acknowledging you have one.

BTW, that dealership, Crossroads Ford at I40 & I240, has since closed. And I hope, for the sake of future Ford buyers, that Ford doesn't allow the Lewis' to ever have a Ford franchise again.

 

Hmmmm - but is rust still a problem after the Restore+ treatments?
If it's been rusting internally for the past 5 years I figure you'd have sprung a leak somewhere by now.
Do you think it is still rusting or that you are slowly and painfully removing rust that built up starting in '07?
The problem keeps coming back. So either the source is still alive (demonic gremlins with bad hygiene shedding dandruff and causing rust) or the rust from years ago is that difficult to completely flush out. What comes out of the backflush when you do it these days?