yes, I think it is!

I assume the injector throws an error or calls with its cb with cb(new Err(plugin missing: ${name}, null)?

I saw your old branch and revived it as scuttleShellTest.
It uses the shell's API to start it instead of spawn(), which means it should also be bundled when you install pbay standalone.
You can alrady try it if you like.

I'll try and add the injector to test plugin availablility.