TheDuckCow shows how a few lines of Python code can make a big difference in how you use linked assets.
Have you ever library linked a group from another blender file, but wished you could easily modify one part of it? Well, you could always modify the library linked source file, setup driver controls, or… you could use this little trick.
This tutorial was streamed as a part of the 2018 World Blender Meetup Day, and shows how extremely simple python code can "override" library linked data. It allows you to show or hide linked-objects on the fly, swap out linked-images, adjust object locations part of linked groups, and.. well, really anything! The best part is you maintain the library linking (no need to make local or append), and it all works without any custom addons (works fine on render farms, just enable python scripts). This tutorial covers just a few simple examples of useful overrides.
Video tutorial here:
See here the text version of the tutorial, along with source code for quick copying.