Data minimisation vs. utility: can I include "country" or "region" alongside redacted personal data?

Working on a system that redacts PII before it reaches an AI model. Names, IBANs, emails, phone numbers — all removed.

But I'm finding that stripping everything makes the output nearly useless. A redacted IBAN like [IBAN] gives the model no basis to answer "should this go through SEPA or SWIFT?" — but if I keep country_code="DE" as metadata, it can.

Similarly for locations: replacing "Munich" with [LOCATION] loses the jurisdiction context. But [LOCATION scope="city"] or even [LOCATION country="DE"] keeps it.

My read of GDPR Art. 5(1)(c) is that data minimisation means "adequate, relevant and limited to what is necessary." If the country code is necessary for the task and does not identify the individual, it should be fine to retain.

But I'm not a lawyer. Has anyone dealt with this boundary in practice? Is "country derived from IBAN" still personal data if the IBAN itself is removed? What about gender inferred from a title (Mr./Mrs.) — is that special category data under Art. 9 even without the name?