This line is kinda confusing, tbh. I'm not really sure at first glance how it might be different than the previous one (since it's not clear this is about non-registry packages).

I think I saw <pkg> used in another place to mean <folder|tarball|git url|user/repo>. Maybe a way to say everything else is just forwarded to npx.

I wonder if we could do more here. Should we also, maybe, handle hosted git deps? npm init zkat/templ -> npx github:zkat/create-templ? What's the expectation around this? What makes these others any better than doing npx file:some/initializer?

What makes these others any better than doing npx file:some/initializer?

At the moment they aren't any better than using npx. We could keep it simple. When a user provides a non registry name to npm init it could just recommend using npx instead. Something like

$ npm init file:some/initializer
> Unrecognized initializer: file:some/initializer.
> For more package binary executing power check out `npx`:
> https://www.npmjs.com/package/npx

Ok, I've updated the PR to more gracefully punt on git, path, and url names for now instead of just erring out.

This should probably be an actual error. Maybe with err.code === 'EUNSUPPORTED' or something? 🤔

Ah ok!