One of the principles that stjepang was very keen on for smol was that libraries
shouldn't depend on it. Libraries should be written in an async-executor generic way and the end binary should then be free to use smol as the executor, or tokio, or anything else.
I'm currently using smol (in an application I'm developing - not just a library) and I don't think this will scare me away. He appears to still be responding to pull requests, and smol consists of a reasonably small amount of very high quality code.