Proxies started getting blocked (by some auth-account methods) last year, but libreddit/redlib dev was able to outsmart them multiple times. Now it seems like reddit is blocking IPs (and/or IP ranges). Running redlib from a residential IP still works, but I would not expect it to work from a VPS.
.NET applications using .NET Core or later are intended to be cross-platform, so technically, Linux can run .NET apps. (The use-case I know is running .NET sites on Linux servers)