To be fair, even in his best ending, Jarrod strikes me as kind of an “out of sight, out of mind” kind of guy. I can’t really see him putting in the effort to write letters and keep up correspondence with anyone who isn’t directly relevant to him - so maybe it would only be viable to stay friends if the MC ends up in Revaire at the end of the game? Not sure if he gets any extra epilogue content on those routes or not.