In short, no.

We used to deal with this by identifying recorder outside Recorder 6  by taxon group as part of a verification/validation workflow, exporting records in bulk then using a batch update to change the verification status of those records en masse.

We added a 'Duplicate' term to the verification status list (linked to failed/pending).

Where records were considered duplicates we would then do a Batch Import against the Duplicate term to mark all records as such.

By marking records in the database this allowed us to revise or at least otherwise track that judgment in the future should we need to. I imagine a batch update to delete such records could be done in much the same way once you have the 'taxon occurrence keys'. However, you'd need to make a decision as to which survey takes precedence over other surveys where a duplicate record exists in more than one.