I think the state of the literature is a little more complicated than you surmise from Huberman's podcast. For example, note especially their careful wording around its neurotoxicity, as well as the clinical dosing assumptions they make their claims within, which likely differ from those of casual users. As a cautionary example, you should look into alpha-Methyldopamine. Last I checked (which was, admittedly, several years ago), there was not a good rebuttal to its neurotoxic potential. Though this potential is less serious than the neurotoxicity demonstrated by the botched study which injected methamphetamine and said it was MDMA (and was later corrected, but the damage to MDMA's reputation had already been done), I still think it demonstrates that the case of MDMA's neurotoxicity, at least in the way that a casual user might consume it--even sparingly--is not an open and shut case.
That said, I'd love to be proven wrong, since MDMA is great stuff. I hope someone can check the most recent literature on this topic and tell me otherwise.
Another class of putatively non- or less-neurotoxic entactogens I don't see mentioned here are aminoindanes, which David Nichols' group specifically engineered to have lower neurotoxic potential. The classic prototype here is 5,6-methylenedioxy-2-aminoindane, or MDAI. It's also worth considering. The other broad classes of potentially non- or less-neurotoxic entactogens which I'm aware of, other than aminoindanes, are benzofurans (which are covered in the article) and substituted cathinones. Imo, all three classes contain molecules which are just peachy :) I recommend (prudent) exploration.
As another commenter noted, some people have trouble with nausea when taking shrooms. If you're in this camp, I'd recommend exploring O-Acetylpsilocin (aka 4-AcO-DMT), which is widely thought to be a prodrug for psilocin, and much easier to synthesize than psilocybin to boot--and note that psilocybin is a prodrug for psilocin too, after all. Having explored both fairly extensively, I think O-Acetylpsilocin holds a lot fewer surprises than shrooms. I expect that pure psilocybin would behave similarly, but I haven't experienced it.
L-Theanine is somewhat sweet and... chalky, perhaps. It's a little savory/funky too. Not altogether an unpleasant flavour. I occasionally take a teaspoon of unpacked L-Theanine powder and stir it into a glass of water. It doesn't mix very readily, but once it does, it's barely noticeable (at least to my palate). I don't notice it when I repeat this process with green or black tea, so I would be surprised if anyone could detect it in coffee.
That said, I'd love to be proven wrong, since MDMA is great stuff. I hope someone can check the most recent literature on this topic and tell me otherwise.