We currently support vim8 async formatting by using its jobs API. However neovim job/channel API is not the same as vim8.
In order to provide a better experience for neovim users we should also support neovim job/channel API.
After doing some investigation, the technical debt added to support neovim async / job is way too high.
For now will be closing this issue until neovim / vim8 iterate on their async/channel API's