Please check out https://github.com/d8ahazard/FlexTV.bundle for the latest iteration of the plugin.
Also, there's an experimental stand-alone app for homes without a PMS server, but you want to control cast devices at https://github.com/d8ahazard/FlexConnect - and docker - https://github.com/d8ahazard/docker-FlexConnect
If you have issues, feel free to report them there!