Thought experiment regarding the endgame

[Romulator]

It'd still follow the same scenario. Both characters wake up and live on as copies in their own individual lives; possibly even unaware of whether the other exists. Simon is incapable of realizing that there are a few of him already, because he constantly finds himself under the impression his whole self is carried over.

When transferred onto the ARK, he believes it worked. When his robotic, structure gel infused self is not transferred onto the ARK, he blames Catherine for lying to him. There's a Simon at the bottom of the ocean in a chair; and another floating on the ARK.

As for whom you possess, it depends on whom you are. You are your own self in either a real, manufactured, or virtual being. You would control both, but neither other influences the choices in the seperate body. Mind A controls Simon-2, Mind B controls Simon-3, but Mind A nor Mind B can control the other.

So, you're within both, regardless of the sleep; and you will believe whichever mindset you end up in was the successful one.