How external modules/dependencies would work

Right now, the app looks for specific modules outlined in modules.json in the lib/middleware/ folder. It also pulls all dependency requirements per module from the global package.json.

I was wondering:
1. If people were to build other npm packages as extensions/alternative modules, how would I allow users to install those? I guess the more specific question is, do I look for global modules as well? E.g. instead of `this.use(path, require("./middleware/" + module))`, maybe something like `this.use(path, require(module) || require("./middleware/" + module))`.
2. Design-wise is it better to remove all the integration dependencies (client libraries) from package.json? That way, the user won't have to install packages for integrations they might not use. Or maybe better yet, there is some way to choose the integrations while they are doing `npm install`. Food for thought.