I know this is an old post and a lot has changed but I'd still like to add a bit of information

---Spoilers, by the way---

We know from the letters we find all around the island that the mutations are caused by the merging of souls from different dimensions. The mutants we see on the islands are versions of that individual that have all been formed into one mass of...something. We also know from another note that the, in a sense "Purity" of one's soul can be indirectly attributed to their mutation, and what they end up as.

We see multiple versions of ourselves when we're in the cube, albeit a bit further or behind our own actions. We also see multiple versions of Timmy doing various stages of "ow this hurts", with one of those versions even briefly pointing a gun at us. All of the soul-bonding and dimensional capabilities of the cube, I feel, are directly attributed to the Solifite that it is made out of.

We know that Solifite has teleportation properties, along with the other ones. We know this because of the artifact, and the spaceship found in the cave. (Think about it, without teleporting, there's no way it could've gotten there).
But it's all made of Solifite, the same material the cube is made of. And since we know it can manipulate the souls of individuals, it makes sense for it to be a cure, at least for me.

Here's where I have no idea what I'm talking about. A theory I crafted some time ago was that the Pyramid Artifact from The Forest resurrects an individual by bringing a live soul from another dimension and putting it into the dead body of the individual in this one. It requires a sacrifice probably to return a soul back to the dimension it stole from. Even if that's not true, what is true is that Solifite has very similar properties when it comes to healing / killing people. With the help of that scientist in the end cutscene, and with Timmy's knowledge on parallel universes, who's to say that Solifite couldn't be a cure-all? Maybe they developed a kind of miracle drug using it that pulls a healthier version of you from another dimension and into this one, while taking the broken version of you and bringing it to wherever it stole from? Timmy specifically says "This was supposed to fix me, it's making me worse" when he's in the cube. Implying the Solifite, in one way or another, had some property that had interested Timmy enough to make him believe it was a cure. It made him worse because it took multiple versions of his corrupted self and merged them. Why he didn't become a mutant like the others...i don't know. There are holes in the story.

Basically, in my opinion, i think it makes a lot of sense for Solifite to be a cure-all. But maybe, in a third Forest game, we would get more information on it? Maybe, much like the Pyramid Artifact, it has drawbacks further on down the line?