Been there,
I feel your pain. I've been that KC10 back there (albeit with a perfect closure of course ; )
Let's remember that it's the 135 autopilot's inability to cope with those rapid trim changes that is a big factor in that particular situation.
Interestingly, other nations, when considering a tankers action in the event of an emergency separation, do nothing ........
If the FADEC issue is still there, then that is indeed an issue, but I thought there was a modification to allow full range of the engine parameters ?
Diff may know .......