Well, I don't like writing much because I tend to write too much when I start; that's because English isn't my native language (I speak Spanish), and to say that I'm a terrible writer is giving me too much credit xD, so it's not a good combination, but since we're talking about memory, I think it's good to give my point of view.
I believe there are things we need to take into account when theorizing about the path of memory (and, for that matter, other paths). As I see it, “all roads lead to Rome”; I believe, as is logical, that more than one path is capable of entering the territory of another, but there will be paths whose abilities are better or more akin depending on the path itself. I think WW wanted to orient the paths, in addition to their definitions, also to where they focus. In the case of authority, what differentiates it from truth? Because truth cannot give a command where the result is generated by an action other than the action performed by the person, why not say “you cut your own throat” and objectively make it a reality? It would have to be because authority needs to influence something with will. We did not see anyone in authority able to give orders to something without consciousness, but we did see it in truth (since authority comes from order, and from what we can see, order is the laws that govern this sphere, we can say that without power, authority cannot touch what it does not have will over, or at least what we have seen so far). I can believe that this is not absolute because there are some mutations, but for now, without mixing other paths, it seems that the limit of authority lies in what has consciousness. At the same time, we don't see Truth affecting people's physical bodies, let alone their minds (although an interesting exception should be made for WW's mention that Truth would be a good healer when it comes to creating flesh, although I think he said that this is in the case of combining paths, since he doesn't want any path to heal on its own, with the exception of Ella xD, although that's another long topic that I've already discussed, and although I don't like what WW did with healing in the game, I understand it narratively), so we know that the limits of the paths to provide balance will be in touching the territory of other paths, but if there is no mixing of paths, it should not be able to do what another does in its entirety, but at most be a few steps behind another, as seems to be the case with memory and illusion, for example.
To theorize a path, we would have to look at the witnesses we already have in the game (in the case of Memory, which is what interests us for now, these would be the MC, Syla, the Sylats, and Lethe Kori, although the latter is unconfirmed), see which ones are pure, since mixing them would give other possibilities, take into account their genetics (which makes them unique and gives them a predisposition to their abilities and powers), corruption (we hardly take this into account, but it is said that this causes variations in the abilities of the spawn, and I don't see why it wouldn't affect evolutions, even if only slightly), and external catalysts (such as the cases of Charlie, the twins, and so on).
We know a lot about Syla, but WW made almost everything we know happen in the intangible world; however, we have the Sylat, and we should think that the abilities they can perform should also be possible for Syla, being their matriarch. The entire branch descended from Syla should be able to do what the Sylat do as long as they are pure, that is, the mind can modify the physical body, but only to the extent of the information obtained, so copying other bodies and abilities is more than possible in the material world. Then the body will go where the mind tells it to, or at least that's the case in Syla's branch (with limits so far on the ability to extract, assimilate, and reproduce information). We also have contactless mind reading, personal realm shifting, and shifting with another person; we can't use the other abilities because they were made in the immaterial world.
There was one thing Syla achieved that I think is important to mention in this case: her DNA was modified by her fear of lightning (evolution is adaptation; ideally, it should be something positive, but unfortunately, that's not always the case), and it caused weakness in both her and her entire lineage, but in her final moments, that weakness was modified again to the point where it became something that could absorb and give her energy. the body does not have this trait of subconscious adaptation.
Now let's move on to Lethe Kori. I know she's not confirmed, but based on what she tells us she can do in the nightmares she gives us (she was able to change a person's gender, so it seems to me to be a memory implementation) and her desire to obtain more memories, her ability to change realms, even partially, to become intangible, I think she has enough points to be taken into account. The problem is that, since we can't confirm that she's pure, we can't be sure that intangibility is unique to the memory (although it makes sense). We know she's not descended from Syla because she doesn't refer to her as matriarch.
In conclusion: We have a change of realm (even if it is partial, although I think that is even more broken), a change in physical appearance at the template level (this includes unique things like Syla's Egregor, although I think it requires a massive amount of memory to use it), mind reading (without contact and within a certain area), information imprinting (making people see memories), information storage (as we have seen, objects can store memories, power, abilities, etc.), memory storage (a greater capacity to store information), memory implementation (they should be the ones who learn things most easily, with their limit being whether they understand them, although logically even that should not be a limit), control of information input (sight, smell, hearing, etc.). I would add the editing and copying of information, but I can tell you right now that WW doesn't want that for memory xD; it wants memory to be like a coin that can be given away, and when you give it away, you're going to forget it, whether you want to or not xD. That and, apparently, to be stronger in Memory, you need to store as many memories as possible.
For now, I think that's all for what I consider to be the realm of pure memory. It's important to remember that, even if something may seem logical, WW will also limit it based on the other points I mentioned above (genetics, after all). I think a good example of this would be Ella and the last villain we faced (I can't remember his name xD), both pure bodies, but with very different orientations.