Since 2.81 Blender has a new override system, which allows for instancing and locally changing values of objects from different files. It also has a system of instancing collections. However, the overrides can only be applied to linked collections from other blender files and not to local collection instances.
Scenario: file1.blend
– Door (Collection)
---- Door (Object)
Now you would be able to create a collection instance of Door in file2 and activate Library Override for this instance. You are not able to create a collection instance of Door in file1 - which could be quite helpful.
In summary I think, Library Overrides should be something like general “data overrides” and allow for overriding instance data from the same file too.
Bump! I’ve been building a hallway with several doors. The natural workflow is to make each door a collection including an armature. How do you then open just one door? I know there are workarounds but seems a bit lame.
It’s part of a general issue. Blender still seems to be very old fashioned at heart with a single application trying to do all tasks using it’s own .blend data format rather than a linker/launcher using standard (i.e. long term stable) formats and a toolset. Things have improved a bit but I’ve really struggled with collections and overrides, I find them very difficult to follow and crashy (2.93.6). A lot more work needed by the core team.