Curate, connect, and discover
I think instead of lame excuses like "Cass is away in Honk Kong" or "[x bat] is doing stuff from his team of heroes" or just ignoring Steph's existance altogether, it would be funny if fanfics took members of the Batfam out of comission by having them have their own fanfic-related cliché adventure
Like, a Jason-centered fic where he asks Alfred where is the replacement and Alfred just goes "oh, Master Timothy has just been possesed by himself from thee-years into the future and is away trying to prevent our horrible deaths" and that's it, Tim is having his own time-travelling fix-it fic in the background which is why he's not mentioned
Babs on a Babs-centric fic where she could really use some advice asking Bruce on comms where her Batgirls are and Bruce non-chalantly answers "Steph has been hit by a love potion and Cass has offered to help her to her apartment", Babs waits a moment and comments "oh... do we get the 'congrats on kissing' banner ready for tomorrow?", "no, I think it's a slow burn, give them a week" and the rest of the fic happens without them
Dick, entering a room and finding Duke "hey, is Damian acting weird this morning or what?" "I think he said something about being stuck on a time-loop until he learns the true meaning of christmas" "aren't we on july?" "Yeah I thought so too but when I asked he mentioned he had already gotten my help on two loops so I just left him be" "well I needed help with a case, you in?" and the rest of the fic is a Dick and Duke team-up