This change will ensure at least one 'local' collection can host the new
'local' override of all objects (indirectly) overridden by this
operation, such that no new override of object ends up in master
collection (which can become extremely messy in production files).
In practice, it means often at least one of the linked collection owning
those objects also has to be overridden.
NOTE: This only affect cases where root overridden linked object has
some dependencies outside of its own root linked collection. While this
situation should be avoided, it cannot always be, so we try to support
it as best as we can.
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