Just to keep the discussion alive
I really think that a duplicate feature would be great for comparisons and other things.
Or maybe an "versions" of the same file (some kind of save state, like a GIT) that can easily flip through those model's versions (like a GIT checkout) .
And i see that this could be massive for the servers, to store so many versions, of so many files. So this feature could be "number limited", lets say, for 3-5 states. Maybe more but "temporally", so (in the 3d settings) the user can create some states, choose between the 3 kinds of light of his scene, or 12 colors of the model, whatever, and them only the chosen one keeps permanently (as a GIT branch, them merge).
Maybe even the main 3-5 versions permanently, and inside it, the user can create the temporally changes, choose one, and that keeps as the model of the state.
It quite complex, i understand. But i hope some ideas can be useful.