It's possible. The global flag is just a convention used currently by the standard library. There still are some rough spots, but I've written a TUI chat client

It's possible. The global flag is just a convention used currently by the standard library. There still are some rough spots, but I've written a TUI chat client that uses blocking I/O when interacting with the terminal, while all other operations are evented and use async/await. We still need to nail down the interface, but there is no technical blocker.