Wouldn't it change everything from the perspective of the time/universe traveller though?
nope. stepping out of your universe/timeline to the other only affects that other. course, the smount of time spent outside of your space is moving at its default speed so time in your world will have passed while you were out but none of your actions outside would change anything on your side
Reverse time travel isn't possible, so stop quoting a specific model used in fiction. The rules can be whatever you want because it's just a joke.
Wouldn't it change everything from the perspective of the time/universe traveller though?
nope. stepping out of your universe/timeline to the other only affects that other. course, the smount of time spent outside of your space is moving at its default speed so time in your world will have passed while you were out but none of your actions outside would change anything on your side
Reverse time travel isn't possible, so stop quoting a specific model used in fiction. The rules can be whatever you want because it's just a joke.