DY:
This will drag the thread into a different direction, which perhaps should have a thread of its own (if I recall, there have been threads on this), but i challenge what you wrote: “And it should be limited to Purim and perhaps Simchas Torah when it’s a mitzvah/minhag.”
Our Gedolim have spoken openly about the myth of serious intoxication on Purim as being plain old yetzer horah. It is fairly clear from the poskim that the “dead drunk” is not the intent of the mitzvah on Purim. Next, I still await to hear something reputable about drinking on Simchas Torah. I asked around several poskim and dayanim I know, and none was able to find a source for this “mitzvah” or “minhag”. Someone once challenged me on my revulsion to drunkenness on Simchas Torah by claiming that it was unfair to see it as negative. After a painful month of Elul, with the requisite cheshbon hanefesh and teshuvah, there was selichos, then Rosh Hashanah and Yom Kippur, then the Sukkos mitzvos, one needs a break, and the imbibing on Simchas Torah is that chance to let go. This was cast as if it was Toras Hachasidus. I was as disgusted by this perverse thinking as I am by shikruso shel Lot. Maybe on these two Yomim Tovim, there should be a mitzvah to smoke weed? I am sure the Satan will derive much nachas from this, and I am convinced that HKB”H will not accept this as positive anything.