While I understand your ardent pursuit for the truth (which, intentionally, is becoming harder and harder to pin down) and I highly value you individually for your thirst for instating your right to the freedom of a stigma free and wellbeing infused sentient experience as this is the truest of callings and not all answer that call.
That said I must illustrate that, ironically, even though marijuana does not directly kill braincells (some hopkins studies say use once a week may even donate a several iq points due to increased blood oxygenation) Cannabis is a very high accumulator of Mg (which has high affinity to iron who carries oxygen throughout the blood) and is laden with ALA which carries this past the blood brain barrier into the brian. This is the same reason why there are some advisories about fish oil omega3 supplements because these wonderful amino acids have such a high affinity for Methylmercury. Also reports like Jeremy piven avid sushi consumer being stricken with mercury poison
Most people won't have much of a problem ingesting and releasing given quantities but others who have had mounted mercury Amalgams leaking amounts that wildly exceeds the maximum limit the body can eliminate through liverbile glutathione and who as a direct result have impaired livers and kidneys and a pallete of other health problems, will find marijuana to be quite catasthropic to mental function due to redistrubution.
though admittedly recouperative to the body balance in the short run due to cannabis' amazing amino acid/thc enzyme/micromineral makeup (given the plant is grown organically from non genetically altered seeds and minerally/bacterially/ecologically fertile environment)
this ala/Mg load will negatively impact Amalgam victims. Also it will maximally impact those who have the Alzheimer's genetic predisposition allele APOE e4 which provides no brain filtration pathway viable to eliminate Mg from the brain in a timely manner. Those under that desription, without supplemental chelation practice or diet with compounds that can assist, may find Alzheimer's or dimentia despite any Amalgams due to overall environmental accumulation at any rate. Obviously this is not all of us but these would be the most notable outliers as far as impaired cognitive function with marijuana use goes.
You can find similarity in symptom complaints for those with Amalgams attempting to detox with ala or herbal remedy cocktail supplements (which are also hefty in ala content) describing more mental disturbances and previously unnoticed social anxiety symptoms and dissasociation (lingering on after very moderate use) that Mirrors complaints of *some longterm smokers on mental Health Forums specifically social anxiety/cognitive disassociation forums. These people really stand out amongst the cannabis community because their experience completely contradicts the intended use, consistently.
Unfortunately many smokers also attempt to help these people get over their "paranoia" by smoking even larger amounts. When the symptoms increase some will suggest pretty plainly that cannabis can act as a catalyst for those who already have a genetic disposition for underlying psychosis. This social process is more comically played out in person but is hellishly ostracizing to the people in question.
This really leaves some with nowhere to look but psychiatric help who may unfortunately prescribe addictive nerve suppressants (to alleviate the nerve damaged caused by methlymercury mangling axion sheaths)that can further take the well being receptors in the brain that respond to gaba, dopamine, ocytonin, SSRI past the bifurcation point as the these chemicals conduct no nerve repair, further sinking these people into a mental hurricane of Depression and constant fight or flight adrenal animosity within their inner mental space which can really feel like hell. This is obviously diametrically-opposed to the cognitive repair we are seeking when we say we just want to "feel normal" again. Or maybe thefor the first time.
I want to also connect the claims we have of people who have family members who already have dimentia or Alzheimer's who are being recovered by coconut oil or ala, rick Simpson oil and so on I would like to think here this indicates the other end of the spectrum of heavy metal recovery so we can arrest the bipolar judgement that something is good or bad. I believe it can be very situational and the best effort might be to get a hair analysis done and microflora test done hormonal tests done by reputable companies away from establishments who profit from disinfomation so we can effectually "open source" our own health problems if we have a hunch what they might be and have a credible tested path for recovery.
That said with no impairment to the eliminitory process then I think cannabis is a more benign substance for use and exponentially effeciant for healing a myraid of illnesses but in this specific scenario will severely impair those with heavy Amalgam damage.
There is always the possibility that extemely heavy dosage may provide a pathway to elimination such as heavy dose vitamin c or the Bane of Mrsa which is heavy dose nicotinic acid as I noticed rick Simpson oil does seem to eliminate carcinogens through black tarry residue through the skin and it is already an elimination pathway as indicated by the rosacea or dermatitis/eczema/metal allergy present with mercury toxic individuals but I'll leave that to some more effective research or another brave soul.