For a modern OS developed in a socialist country I'd go with Deepin. It's currently Debian based but I think the developers are working on their own base.
Seeing as the version leaked was released in 2013, I wouldn't recommend it due to a combination of security concerns & hardware compatibility. Furthermore, seeing as the source code is not available, it is near impossible to audit the code. It is my understanding that prior to RedstarOS, they used Red Had Enterprise Linux, so using a recompilation such as Rocky Linux may be a good way to stay close to their OS of choice.