Hey, not sure if it's already known (couldn't find anything on the wiki about it) but I just confirmed that with this mod the backer characters and any other pawns that are tied to a unique childhood backstory are disabled from spawning on the pawn selection screen for all scenarios, possibly also for pawns that join in-game.

I was just wondering whether it was a bug or if it's just a workaround to avoid aliens from spawning with irrelevant backgrounds? I know a lot of people aren't fans in regards to some of the backer pawns but it does lower the selection pool somewhat significantly.