This is super interesting and I'm still going through the paper. For folks with a "Cool, but why" reaction, the introduction elaborates:

  For example, the P language [10] is a language for describing verifiable asyn-
  chronous state machines, and used for example to implement and verify the core
  of the USB device driver stack that ships with Microsoft Windows 8. Compiling
  to C involves a complex CPS-style transformation [19, 26] to enable async/await
  style programming [5] with a receive statement – using the effects library this
  transformation is no longer necessary and we can generate straightforward C
  code instead. Similarly, we hope to integrate this library with libuv [29] (the
  asynchronous C library underlying Node [43]) and improve programming with
  libuv directly from C or C++ using async/await style abstractions [12, 27]

Since the linked abstract doesn't actually mention this practical application, consider this comment as a goad to encourage more people to click through to the paper :)