Moving a components position across artboards in multiple files.

Position of a component instance is not component's property, ie. you can place an instance anywhere you like independent to other instances.

I can think of one way - if you edit your master component to include an artboard size rectangle as "base layer", when you move the component's elements within the base layer and update the library, all of your instances across multiple files will get updated with the new elements positioning. Hope this makes sense.