I first thought of this question when rewatching the part where Abe shows Aaron the mold growth on the weeble--based on the technician saying "it is a joke" etc, we know that Aaron planted the mold to prod Abe into realizing the time-travelling properties of the machine more quickly. Aaron has already time-travelled and in this timeline, wants Abe to more quickly set things in motion than before.
In this timeline, where Aaron induces Abe to time-travel at an earlier point compared to "previous" timelines, how does this affect subsequent timelines that Aaron travels to? So:
Timeline A
Aaron plants the mold | Abe enters his box->Time T in Timeline B | Aaron enters his box
X Y Z
Timeline B
Aaron plants the mold | | Abe enters his box->Timeline B | Aaron enters his box
X T Y Z
Where does Aaron, from Timeline A, arrive? The issue isn't at what point in a given timeline he arrives (that would depend on how he configured the box), but what the timeline that he arrives in looks like. I thought that any time traveller in Primer arrives at a timeline that is an exact replicate of the one that the time traveller just left. So, Timeline A Aaron shouldn't ever encounter any version of the Timeline A Abe that has time travelled, correct? Since, in Timeline A, Abe only entered the box for the first time, and never exited.
Then, the only way that time-travel-inducing Aaron can encounter the time-travel-induced Abe, is if a COPY of the time-travel-inducing Aaron, ie an Aaron from a subsequent timeline that time-travel-induced Abe travelled to, then time-travels.
Is that correct?