Okay. So I found this YouTube video tonight which I THINK explains the thing that's driving me crazy. I think the video author is dead right except for one thing: He thinks that when you're time inverted you're breathing CO2 in stead of oxygen, which sounds stupid. Inverting time wouldn't make your body swap compounds. I'm still for the idea that you can't metabolize inverted oxygen as the better explanation.
Anyway, he points out something that, if he's right, I totally missed. The protagonist that is going to kill himself at the end of the movie in order to activate the Algorithm is NOT the protagonist from the past. Like his wife who went back in time to kill him, the protagonist she kills is also from the future, who went back into the past to bury the Algorithm and kill himself (why he couldn't do that in his own time, beats me) . The past protagonist is apparently somewhere else on the boat (that's a stretch I agree), thus the past is not changed. Everything happened just as it happened. The body that was tossed overboard is the future protagonist. The past version of him continues on, and the past version of his wife becomes estranged from him because she saw a woman dive off the boat from his cabin and assumed that he was cheating on her.
Going to take that with a grain of salt and watch the movies again, but it helps me make sense of the ending.
- "The same idiots whining about cancel culture are the people who tried to cancel pretty much every video game, book genre, and RPG when I was a kid." - James S. A. Corey