Seems like that is just a server implementation that requires you to use stock RustDesk clients. So you can't really have a fully opensource RustDesk-like system without requiring a substantial chunk of unlicensed source code as well as a closed source dll blob(s).

I just glanced over the repo, deployment and comments around it and it seems like unconstrained AI slop or at least the project seems to be led by a person which can't use AI effectively for the purpose of software engineering.