@ross yeah, I've seen diffs in scala stuff out there and seen than sbt header plugin thing, but fortunately I never used it personally nor professional.
Usually for work it's all internal stuff so there's not really enforcement around that 😅.
Spdx is the best 😌. I'm really liking the short name for the license, and not having to add huge comments with boilerplate text.
I've been trying / experimenting with using reuse tool to manage these things and it's kinda nice too.