Duplicate with Connections

With this script you can make a copy of a layer and link all its properties to the original using expressions via the property name or index. This is useful for instances in which you need to duplicate an animated layer but you do not want to spend all your time copying and pasting keyframes just to update it. For example, you may want to have a camera in a nested composition duplicating the movement and properties of a camera in a main composition. After running this script you may choose to disable whichever expressions you will not need. Note that expressions can slow down a project, so you should use a combination of disabling expressions and converting expressions into keyframes when appropriate.

There is an option to use relative or absolute paths with the duplicates. Choose absolute path if you plan on pre-comping or copying the duplicated instance to another comp. There is an additional option to use the index of the property instead of the name.