aeScript – True Comp Duplicator v3.9.13
Win/Mac | After Effects CS3 or Higher | Size: 69 KB

Creates a complete duplicate of a comp hierarchy including sub-comps.  If a comp is used multiple times, the comp only gets duplicated once and all remaining references point to the first duplicate.  If the comps are arranged in a special folder hierarchy in the project panel, that folder hierarchy is preserved or duplicated (depending on user preference) for the duplicated comps.