Blockstream.info have provided a similar service for a while. Here are a few recent transaction which breach some of their privacy heuristics:

"Round payment amount", "Mixed script types", and "Unnecessary input heuristic" - https://blockstream.info/tx/3ad7e8b8a0240b19703a2681e09079aecaba7ac4e5520d4a4ff42b1c86586ff6
"Address reuse" and "Mixed script types" - https://blockstream.info/tx/2ce5ce8040cc91172919eb81a581be4cc9c78d2e316a4f503a83c597d5e86a63
"Possibly self-transfer" - https://blockstream.info/tx/6b5e6d51370ee9844f61d427a4d0c7826028fc77299dfcad5bd1e403fa56cd74

And an example of a "good" transaction - https://blockstream.info/tx/acf8cf5a2b3e3c60b81cf5c3f76682d12e26cf053f5f0e27ff099b1fc1860dee

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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?