I see on the landing page a screenshot with "Test for GDPR PII compliance", suggesting that this tool is probably not ready for any serious usage.

Anyone in the regulation landscape would know that GDPR is a EU data protection law, and PII a US concept which doesn't apply in the GDPR. The GDPR uses the concept of ‘personal data’, not ‘personally identifiable information’. This is not just a wording issue. Redacting, masking, removing information which appears to be ‘personally identifiable’ only constitutes pseudonymisation in the GDPR which does not offer any meaningful privacy protection.