I work on the Startup.Focus team and was recently helping a startup with their NodeJS development.
They wanted to include some public NodeJS modules but were running into package not found issues.
...
npm ERR! 404 no such package available : node_pkg
npm ERR! 404
npm ERR! 404 'node_pkg' is not in the npm registry.
...
I knew this was an issue with the default configuration of the di-local-npm-registry and wanted to have a nice way to explain the how and why of changing it to search the public registry.
I ended up creating an example project to illustrate the issues and reasoning behind the fix.
https://bitbucket.org/alunde/mta_upstream_registry
If you are running into similar issues, please take a git->clone the project into your server and build/run the web module for more information.
Hope this helps someone out there.
-Andrew