The closest I've seen to having a modern take (in both theory and practice) are 'communalists'/'democratic federalists' into Murray Bookchin's ideas. There's also Kevin Carson, an anarchist theorist big on horizontalism and network economics, but I haven't read his work at length yet.

It saves a lot of stress to ask fired-up people what it is they're for (methodologically speaking) and not bothering to argue if they don't have a coherent or actionable answer.