Overall, this was a novel concept but I feel that it didn't have as much of a payoff as there could have been. The ending does not really build upon the first addendum that much, so it doesn't do a good job of tying the story together. It could have taken the story into an interesting direction, explaining why this person writing the books is so useless and high. What are their motives? How do they have this temporal ability? Is their dependance on substance abuse a product (direct or indirect) of their anomalous ability? Of course, you should not answer every question, but right now, the questions answered in the ending are less interesting than they could have been, in my opinion.
There are some minor things that I found to be a bit on the side of breaking clinical tome. Saying “whichever” and “whenever” feels too casual. This could be fixed by reversing the phrase order of the sentences. “On hand” is also a bit colloquial.
to represent the sequence of what when the the displacement occurred
This part seems like an extra word was intended to be used but was forgotten to be added.
RPC-916 would be disregarded as a non-anomalous
The “a” should be removed.
How much shit should I shove up your ass before even try to make this work?
Seems like this sentence is missing the word “you” after “before”.