I can't currently look into this too much, or even watch the videos on the topic. However, I have a lot of experience in biology (have a degree in it), and thought that my two cents on the topic might be of some interest to those who are interested in the topic and in particular the biological aspects of this issue.
The biggest single issue with things of this nature is that they simply aren't studied enough for someone to give a solid recommendation because we simply don't know the long term effects. Think of it like this. If the thing that the drug is meant to help is really important (say HIV medication for instance), then the willingness of the users to overlook side effects, even hard to guess, uncommon ones, is fairly high, because the reward of the medication is high enough to offset those effects. But with things like this, more or less recreational uses, there isn't anything to really offset the possible negatives. So we can't say that even though we don't really know, you should use it anyway. The reward isn't worth the risk, because we don't know the possible effects.
On top of that, compounding the issue and expanding it some, is the funding aspect. Research into commercial products is really convoluted and often very shady. Think about it. Big corporations which stand to gain or lose tons of money have the motive to try to influence results. And at the same time, studies on people cost a lot of money because there are a lot of hoops to jump through and paying participants is not cheap and you need solid results for your study to be of use, meaning it needs to be fairly big. Who has the time or money for things like that? Big pharma. A lot of conflict of interests and whatnot go in to things like this. I've done a lot of research on a lot of various topics in biology (ranging from molecular mechanisms of intracellular trafficking to sex related defects), and let me tell you. The hardest topics to find real solid research on is medication that is being sold (not always, but very commonly). Once the pros are verified, the side effects and possible unknowns are often overlooked and like I said, things get convoluted. It is a real pain in the ass. Think of where money/politics meets science. The scientists don't end up happy in those situations.
And to make all of this worse, there is a lot to try to understand. Things involved with the brain are very intricate and we have a rather limited understanding of it all. Anyone who tells you otherwise is blow smoke out of their ass. The more you learn about these things, the more you realize how little we know about how things actually work. Let's just say that the innerworkings of the cell are very intricate and the brain most of all. So trying to understand how something affects your brain, not only how it does the intended effect, but how it would affect the rest of brain and how it could cause any side effects and other impacts on the body; it is really hard. It would take a long time and a lot of money to get real solid answers. And with things as nonessential as improving gaming and the like, the money and interest is not there to conduct these experiments and studies. A lot of work goes into understanding these things.
Think of this. Heroin used to be sold as a cough medication. Heroin. It helps coughs really well. I mean, it has some other effects too, but who cares about that? The way we can make money on it is as selling it as a cough medicine. Don't worry about what else it might do. Look, it helps coughs really well. Just don't pay any attention to anything else that it might do.
I'm not saying that there is any malice or anything involved with drugs like this, but you just have to be very cautious. Money clouds things. If they are interested in these numerous drugs as helping cognitive function, they likely are too fixated on that to notice other things that it might be causing. So until there is enough information out there to have a solid conclusion about it, I wouldn't personally recommend them. Though because there are so many, there are a lot of different trade offs and some might be more harmless than others. You have to look into them one by one and then in whatever combinations they might be used as well. The info simply isn't there to allow me to declare it safe for such nonessential needs.