This is a weirdly defensive answer. I didn't attack you personally, I brought up well-founded risks.
Your suggestions, while interesting, don't remove these risks. Yes, certain types of abuse make it worse: dosing higher, polydrug abuse, hot environments, and dehydration are all ways to damage your brain further. However, use of MDMA in an ideal sense probably still causes some level of damage.
https://pubmed.ncbi.nlm.nih.gov/16472832/
2mg/kg dose, so ~160mg for an adult human. More importantly rat to human is usually a 6ish HED factor so that’d be <30mg. In reality metabolism, brain volume, etc all matter but this is not an even remotely safe drug.
This isn't a "purely theoretical exercise", most of those are established mechanisms of amphetamine toxicity. This isn't "listing possible mechanisms", this is sharing salient info of risks of which possible abusers (given the nature of the thread and discussion so far) should be aware.
I'm sure as heck not "ranting out behaviors that would scare a layperson". Most of what I listed is pretty comprehensible with a grasp of high school chem and bio. Most of the information for this is freely available online. The information we have should scare a layman out of use, and probably someone with a greater background, too.
Whatabout-ing with sleep deprivation or similar doesn't make sense to me either. Did I say that was good or healthy? Bad things stack. Your body doesn't keep a record where it says "you've accumulated 10% damage from an un-fun cause like exhaust or sleep deprivation, so now you get to experience 5% damage from a fun cause like molly." That's just a really weird way of thinking about this.
People are within their moral rights to run the risk but I don't understand this defensiveness that it's somehow a good or smart risk to run for the average case of abuse.