Thanks for your reply.
I agree with your analysis to the extent that a primarily Justify/Assumption dichotomy may outcompete a primarily Sufficient/Necessary structure for many practical cases. I disagree, however, that the "term—Justify the Conclusion—more accurately describes the process [we] are asked to complete."
For example, PT 12, LR 1 #22, the stem asks "Which of the following is an assumption that would allow the company's president's conclusion to be properly drawn?" The current LRB clearly categorizes this stem as a Justify question (LRB 2022, p. 346 top half), thereby leading a test taker to search for an answer choice that sufficiently proves the stimulus. The correct answer choice, C, however, is not a sufficient condition, but rather a necessary one, as Kelsey points out on the forum (viewtopic.php?t=6106
I understand that the Justify/Assumption dichotomy works for most testtakers in most situations, but in situations like this, the Sufficient/Necessary would not have led to the misinterpretation of the stem.
Also, I'm uncertain of your point that "'Sufficient Assumption' actually tells you little to nothing about the process unless you understand that ultimately you are justifying the conclusion." First, my perspective is to label the question type Sufficient Condition
questions and entirely drop the word assumption, which I see as at least occasionally unnecessarily misleading, since both Justify and Assumption questions under your paradigm conceptually can be categorized as assumptions, i.e. not only can necessary conditions be categorized as assumptions, sufficient conditions can also be categorized as assumptions. This is further supported by the LSAT's usage of the word "assume" in what you label as justify questions. In my head, the term 'Assumption' in the Justify/Assumption dichotomy is therefore not mutually exclusive and collectively exhaustive, since they are not mutually exclusive in all cases. Conversely, the relevant population of questions either seek for a necessary condition or a sufficient condition.
Curious to read your thoughts. I started at a 149 two months ago and I'm already PTing in the high 160s—once again, thank you.