“The letter seems to be intentionally inexplicable.”
If you found it inexplicable, it may not have been meant for you.
Growing up with a similar mindset, I understood it completely.
As a kid chumash Rashi were drilled into up. In second grade we learnt Chumash Rashi till Sheini, third grade till Shlishi etc
To this day I pretty much remember most Rashis at least until Chamihsi having learnt them again year after year (excluding the “summer parshiyos”)
After getting married I lived in a small out of town community for a few years. This was my first real exposure to, “non-black hat” groups. One fellow gave a Chumash shiur before Shcharis on Shabos, that I sometimes attended. He asked a question “Why does Yaakov seemingly brag to Eisav that he has Oxen, donkeys, sheep slaves, wouldn’t that upset Eisav more (This wasnt actually the question, I’m using an example from this week’s parsha) Different people gave their own answers and interpretations.
I was a bit puzzled, when he asked me for my thoughts I said, a bit perplexed, “I don’t understand the question, Rashi explains it” he replied, “I know Rashi has a peshat, what do you say” To which I replied “It doesn’t matter what I say, Rashi already commented”
now, I’m not convinced that his way is wrong per se. but the authors of the kol koreh certainly do, THAT is the community they are coming from