Well what I want to rebuke is the idea that 4-AcO-DMT possesses unique effects of its own, different than those of psilocin/psilocybin, that are independent of its prodrug-activity and its pharmacokinetics, in other words, that it not just a way of getting psilocin to the brain, but is actually an "active" drug. This is a very common belief among us "tryptamine enjoyers"
. However I do think it's false for a number of reasons, the most notable being that simply of the placebo. When you eat mushrooms, you are quite literally consuming an organic, fleshy substance that grew out of the ground (or more likely a shoebox under some dudes bed), where as when you take 4-AcO, you are taking a white powder that you got from the internet, produced in China. Therefore, its fully reasonable to assert that the common claim of "4-AcO has more synthetic visuals" is merely a placebo
only from the synthetic appearance of the drug, and conversely, the "organic" visuals of psilocybin being only from its natural appearance. I don't actually think that any slight chance to the drug's structure could significantly alter the visual profile of the drug, especially considering how nebulous and vague "synthetic" and "organic" visuals are as a concept. If you don't believe me, then consider how funny of a coincidence it is, that the only psychedelic that has a "nature-like feel" constantly attributed to it, is psilocybin, which just happens to be present in a "natural" form (that is, the mushroom). The psychedelic experience obviously leaves us extremely suggestible, so to think that one couldn't have very different experiences based merely on pre-existing beliefs, is naïve. Similar experiments of self-suggestion influencing a trip (and with only a single compound, LSD) were carried out by Leary.
As for as actual metabolism goes, the acetyl group is also known to get rapidly cleaved off in the body, and it's unlikely that there even is a lot of 4-AcO-DMT left in the body after, say, 30 minutes of ingestion, rather, it's all converted to psilocin. There's also no change of the effect profile anywhere during the trip, which is what we see with drugs, where both the pro-drug and the active metabolite have different effects (like dextromethorphan and its breakdown product, dextrorphan, which are both active, but in different ways). The 5-HT2A receptor is also probably too tight to accommodate such a large group as the acetyl group (whereas we know that the hydroxyl group of psilocin is a near-perfect match for it.) Rant over.
As far as the metabolism of literally every single human being goes, that's perfectly within standard deviation. The difference between an 8 hour trip and 10 hour trip on LSD is proportionally the same as a 4 hour trip and a 5 hour trip on mushrooms, yet no one would claim that even a mushroom trip of 3.5 hours or 6 hours is of unusual length.
