Couldn't find the original message to reply to, but #1 I'd like to see the RFC actually fleshed out. There's a PR linked, but we should define the actual goals/APIs etc... in the RFC itself as well as the numerous edge cases Christophe noted and why they aren't (or are?) concerns.
I do recall discussing this with Wez many years ago and the sharp corners felt like a "wait until someone is asking for it" kind of situation. -Sara