and it is good to keep in mind that whenever you search your own address or transactions on any centralized database aka a blockexplorer you are willingly giving them a lot of information about yourself that is leaked from your browser and that blockexplorer could potentially store it and use in their hidden chainanalysis services they offer to other parties...
Can you elaborate on the "rare_fingerprint" category? What specifically is your algorithm looking for? As far as I can tell, any transaction with a lock_time other than 0 is flagged up as having a "rare_fingerprint". Given that Bitcoin Core sets lock_time to the current block by default, that means any transaction from Bitcoin Core is being flagged up as having poor privacy. Is this intended?
actually Core and some others like Electrum are setting the locktime to a random height below the current head.
their doc doesn't explain what that field means though, there is only a generic description "This transaction has quite unique technical characteristics"