The whole idea of imprinting in 'Twilight' is already a huge point of debate in fandom, and fanfiction writers have gone absolutely wild with it, especially for Jacob and Renesmee. A lot of stories start by completely rejecting the imprint as some sort of magical love-at-first-sight bond and reframe it as a curse or a compulsion. They'll have Jacob fighting it internally, full of resentment or a twisted sense of duty that feels more like a psychological prison than a soulmate connection.
From there, plots tend to branch hard. One common route is a slow, painful evolution from servitude to something resembling genuine, chosen affection, but it's always shadowed by the initial violation of his will. Another path I see a lot dives into the mechanics of the supernatural world, treating the imprint like a magical glitch that needs to be 'fixed' or broken, leading to crossover AUs or fics where Renesmee ages normally and has to confront the weirdness of her own existence. Honestly, the fics that make me most uncomfortable are the ones that double down on the romance angle but try to 'age up' the premise, which... yeah, never quite lands right for me.