NFS v4.2. Easy to set up if you don't need authentication. Very good throughput, at least so long as your network gear isn't the bottleneck. I think it's the best choice if your clients are Linux or similar. The only bummer for me is that mounting NFS shares from Android file managers seems to be difficult or impossible (let alone NFSv4).
Yes, that's what at least the `nfs-server` service on Fedora does by default. And VLC also supports v3 on Android… maybe they use the same implementation as Kodi behind the scenes? It's weird the v4 support is so spotty still, even though it has been around for two decades. Even NFS v4.2 is almost ten years old at this point.