> I hope this is the right place to ask

this is a very "general discussion" channel, all questions are welcome though some may be directed elsewhere if they touch a specific topic that another channel specialises in.

> embedded-hal-nb is:

a thing that exists because async didn't exist in rust yet.
if you're implementing it to learn why you should probably use async instead, maybe that will be worth your time?
but i think you'll get more out of the ecosystem if you use what already exists first to get a feel for it.

> stable (v1.0)

there are more important signals than version numbers that you should be thinking about, especially when it comes to rust's variant of semver.
like how actively developed and maintained a crate is, how long issues/PRs stay open, etc.
i would much prefer an unstable crate that will take my fixes in a timely fashion