> Julia (along with Elixir) are somewhere in between: All design talk and decision making is public and relatively centralized on GitHub issues.

I think this is an idealized description. From the iteration blog post: "While one of many issues on multi-line comment syntax has 121 comments, the iteration overhaul proposal just says ‘we hashed it out at JuliaCon’ and there’s no mention of alternatives or tradeoffs considered."

> you'll probably see something similar pop up when the time savings provided by a more structured/formal process outweighs the overhead of additional formalization

Imho time savings aren't the main benefit of formal proposals. Rather, the decision outcomes are improved.