Something’s that never been done before — is also because, simply, it’s never occurred to anyone to do it, before!
Given the all-sorts-of-problems people’ve been having with adjusting to timelines, (narrative) arcs, what you’d have to call “Aging,” this film, as it does show us, makes things discernable — and therefore graspable — in ways that no-one can predict, the end of, exhaustively (it has to hit, and keep hitting, person after person, after sets of persons, after more sets of people).
As one of those all-too-many twenty-year-olds that saw Slacker (and pored over the book thereafter) in (in my case) 1992, I’d only have to add: As if we didn’t owe him enough . . .