By backup literature do you mean commentaries of some modern-day scholar monk? If so who cares? Ven T is yet another scholar who has given his own interpretation to the sutta. The sutta alone makes no vivid claim on an after-life hell. If you think it does, quote it.
I have given you 2 sources. You have given none. The Widsom library site you gave provided the definition of the word 'parikuppa' which either translated as 'agony' (Ven. T.) or 'festering' (Woodward). Since it's a website that gives just a definition, tell me the exact source and the author who translated it please.
No mention of "incurable" there. I hear metta.lk has similar translation but I have not been able to find the sutta there. You have come up with some translators who agree with Ven T. Are you saying other sources are all wrong while only the sources you want to believe are right?
What other sources? You have shown none so far. I've shown you two already and they both agree with each other. Your claim about Ven. T that he simply "given his own interpretation" is flat out wrong..