That's interesting. Having learned Haskell long before Rust (and having been programming in C++ for a long time) I found Rust's ?-notation to be annoyingly limited due to the reasons you gave, and also annoying syntactically. I saw in many Rust sources it's often tucked away at the end of lines, flush against the last character, a single character which changes the meaning of the line, well, the whole function, but is often lost to me visually, and I have to scan the line to see it. But I guess people got used to it or just don't bother parsing all characters in a line of code like I do.
When you say "They’re still trying to get the migration done today... " you mean Rust's core developers, right? Is there anywhere I can read up on it?