I don't recall having this conversation with Transmodiar, although I do remember a discussion between him and Recall317 where they discussed how "Obsession"'s psychic characters who can predict the future accurately cast great confusion on SLIDERS claiming in other episodes that every event has multiple outcomes that result in the creation of one parallel Earth for each possibility.
Personally, I file questions regarding the mechanics of the multiverse next to where Arturo always got a fitted, tailored suit and how the sliders could alternate between the same sets of clothes despite never carrying luggage or how they had money given they stopped trying to find jobs after Season 1 outside of "Fire Within" and "Java Jive."
The real world explanation for why SLIDERS in Seasons 1 - 2 generally explored branches from a version of history similar to our own -- it was a TV show written and filmed on our Earth with all the inherent limitations of our reality and our frames of reference.
The in-universe explanation for why this was the case, if you really need one, is that the timer was a damaged and malfunctioning device that could only follow the path of least resistance in identifying branching points to which the sliders would travel and the closest branching points would originate from the sliders home Earth and variants within that particular history.
However, from Season 3 and onward, all that goes out the window when the sliders encounter dragons, intelligent flames that can talk, vampires, super-snakes and a double of Quinn Mallory played by a different actor. We seem to gravitate back to the Season 1 - 2 template in "New Gods for Old" when Dr. Diana Davis remarks that the sliders seem to be encountering, in sequence, different outcomes to one specific event.
But I have to confess, I don't really find these questions about SLIDERS all that interesting. I'd be more interested to contemplate how we might take the time-is-behind idea of "The Guardian" and do another variation on it -- with a story where time is ahead, and leading to a plot where we can look at Quinn's retirement and his death and the legacy that sliding would leave behind after the original sliders are dead and gone. Perhaps Quinn, at age 46, encounters a strange gateway in his basement office. He steps in to find himself in an aged version of his basement filled with artifacts of 45 more years of adventures and seated in a chair is an aged Quinn Mallory. This Quinn-2 is 90 years-old. He has sought a younger version of himself to provide knowledge that only this older Quinn can offer.
At Quinn-2's beckoning, other visitors arrive in the basement: Mary, Rickman, Governor Schick, Mr. Chandler, Bolivar, Ted Bernsen, Cutter, Gerald Thomas, Gareth, Dr. Aldohn, and the older Quinn reveals their impact on the multiverse, showing to our Quinn that these supposed enemies have in fact been a force for order, stability and structure while Quinn's actions throughout his life have ultimately led to chaos, anarchy and death. The younger Quinn is stunned and confused, and the older Quinn summons the intelligent living flame, the strange life form that held all the secrets of the multiverse and the flame offers Quinn another chance at true enlightenment...
Sorry, I don't know where I was going with this and Transmodiar said if I wrote anymore fanfic, he would kill me in my sleep.