I think it’d be really funny to play with timelines just enough so that Jason, after dying and undying or whatever, comes back to Gotham only to see not only Batman having gained like four more kids, but at least half the justice league have a bunch more kids as well.
Batman’s adoption problem isn’t just genetic, it’s contagious and there are so many time travel/dimension shenanigans to work through here, as well as an unsettling number of secret bio kids, and Jason is one more “wait, where did they come from” away from tearing out his hair so he finally decides the rest of his plan can wait. He needs answers.
He’s not going to go ask Batman for anything, obviously, so someone else will have to do. There are many great potential options here, but my pick? Hal Jordan.
Just Jason going to Hal because Batman would never look for him there and Hal wondering how he went from discovering Gotham’s Red Hood in his kitchen to explaining the family structures of the entire Justice League to Batman’s not-so-dead son.