Hi Akvan,
You said: “I agree in principle on everything you have mentioned but I think I am hung up on a few technical words here.”
Yes. I think so.
You said: “What I understand from this is that Dukkha Dukkhatha and Viparinama Dukkhatha can be removed while still alive, while Sankhara Dukkhatha is eliminated after anupadisesa nibbana.”
That is not correct. The reference you gave does not say that. All three (sankhara dukkhata, dukkha dukkhata, viparinama dukkhata) are associated with any sankata. They will be there until the sankata is destroyed. The physical body of even a Buddha is a sankata. It is very clear from the Tipitaka that the Buddha suffered physically due to old age, back aches, and also due to a physical injury.
There is a sutta that attributes all three types to a sankata. It says: “uppado sankata lakkhanan, sankhara dukkhata; vayo sankata lakkhanan, viparinama dukkhata; titthassa sankata lakkhanan, dukkha dukkhata“. I don’t remember the name of the sutta.