While this is a really great project, it has the same issue that all other Swift coroutine libraries have. It relies on setjmp and longjmp, both of which are considered undefined behaviors in Swift (this is the primary reason that Zewo has basically dropped out of SSS). This, if I am correct, still applies to the custom implementations of those methods by libdill.
I'm not too well versed in the top myself, so if you want to know more I would suggest talking to the people from the NIO team.