So while modpacking I found that origins constantly had the selection screen fail to show up due to various hard to track incompatibilities.

The reason seems to be load order related. Here's a case study.

In this log, with a found-to-be minimal setup of Origins, Origins Minus (a datapack in a jar), and FTB Quests - the origins screen fails to show on world load.

in this log, I've added the quilt loader java argument -Dloader.debug.loadLate=origins, forcing origins to initialize latest in the startup sequence. The origins screen succeeds.

Generally speaking, a load order related origin screen fail can seemingly be fixed with -Dloader.debug.loadLate=origins.

In the above setup, the screen fails to show every single time Origins Minus loads after Origins, and succeeds every time Origins loads after Origins Minus (found by spamming different load orders)

This is strange to me, as I would think that datapacks packaged into mods don't really have a "load order" - regardless, I thought I'd formalize this issue and post it here - unsure if "origins is sensitive to data addon load order" is an origins issue or a quilt issue, but this might help a few people out in the meantime.