ZD:
You wrote: “Some Averios people are more willing to forgive than others” I am never able to forgive someone for not putting on Tefillin, missing davening, or chilul Shabbos. Those mitzvos are completely בין אדם למקום, and I have no authority over this. Frankly, someone’s degree of Avodas Hashem is not really my business. My obligation of הוכח תוכיח is a responsibility I have to HKB”H, and I have a mitzvah to say nothing if saying something will not work. Meanwhile, it is commonplace to stand in judgment of another’s status as an Oveid Hashem, and this is a perversion of our role and responsibility. I may be repulsed by the behavior I view in others, but I will never have the privilege to judge. What part of אל תדין is it difficult to grasp? Not even a בית דין has the authority to address these issues. Can you picture a בית דין accepting a defense from a בעל עבירה that he has done תשובה? They cannot, as these are matters that are not in their jurisdiction or domain. It is not up to me whether he should be forgiven.
Remaining with the feeling of disgust some 20 years after he passed away is your privilege, although I wonder if that is in accordance with דברי חז”ל. Once again, this is not relevant in any halachic way with his niggunim as poskim have stated.