What parts have they actually replacing in the rebuilds? I'm sure they didn't replace everything. If they have put the updated CDF and drum in prior rebuilds it's likely something else that is causing poor shifting like a valve body. If the valve body has not been replaced I would be asking about that as it could have easily been contaminated with metal particles when the previous failure happened. I'm not sure I would be going back to the same dealer who has tried to rebuild this already 3 times unless you are confident they have a well trained transmission mechanic.
It’s a fairly large dealer and yes, they have at least one tech who solely does transmission rebuilds (sad state of affairs it’s come to this point). They’re typically booked out a month or two for transmission issues. I’d hope they’ve got their act together at this point.
It’s been a bit since I studied the notes, but I’ve seen at least two instances where they’ve replaced the valve bodies. Definitely they did after the initial instance where they noted metal shavings.
Something has to be shredding these (meaning my) CDFs beyond the original faulty design. Ford apparently has no interest in investigating the cause or attempting to remedy that underlying issue in my case and will continue to throw the least amount of parts at it until they can get past any and all warranty periods.
The cost of buying another Expedition with less miles and with an extended warranty would be considerably more than just shelling out the cash for a new transmission. There’s no guarantee a replacement Expedition would be any better than my current one.