Minor announcement (before everyone runs), I've been working on a crate to handle all the boilerplate of "I want to talk to my MCU over USB using postcard", and just cut the first, usable but underdocumented 0.1 release: https://github.com/jamesmunns/postcard-rpc

If you have need for this kind of thing, definitely check out the `examples/` repo and give me a shout if you have thoughts/opinions.

I wouldn't recommend it for prod just yet, but definitely ready to play around with.

It allows for concurrent access to the device, including for requests that take variable amount of times, and comes with a tokio-flavored host example and an embassy-flavored mcu example.