Let's see what I can do after lunch then. Fun!
Simple rework PR up. I also want to update your BOLT11 parser to the latest (it's buggy). I need to think harder about your cursor API: my instinct is to split it into two types, one for reading, one for writing. But you do a lot of lookahead in your parsing, so the classic "mark cursor invalid if we hit an error" pattern doesn't fit. Hmm....