Why not? For instance, feature proposals are just the previous phase of high-level requirements. And high-level requirements are just the previous phase of (or introduction into) the spec.

I'd think of it as a big documentation where some parts are complete and mature (down to the level of code), while other parts are still in draft (feature proposals).

Or change management: Of course everything should be under version control. And I guess that bug descriptions should still be part of a ticket system or at least the commit messages. But I never understood why feature proposals are discussed more in a discussion-based manner (ticket system) rather than a document-based manner (wiki, or documentation).

Unfortunately, I was never part of a development team which was seriously into LP, so my suggestions are only based on my understanding of LP, and small proof-of-concepts on my own.

I'd love to read about bigger real-world projects which apply LP, or which at least apply some other documentation-driven approach.