Best privacy compliant approach to google ads conversion importation?

Hey All Happy Friday! -

was wondering if anyone has identified the “best way”(s) to allow advertising optimizations based on conversions/goals using by rule no advertising pixels and ensuring HIPPA + GDPR etc compliance.

Currently am relying on Google Ads offline conversion import feature exporting from a Piwik custom report into a Google Sheets that makes required modifications for import. Is this still a recommended approach and how best can one automate this process (some have suggested Supermetrics to Google Sheets Piwik connector - which works - but wanted to check if there’s any methods that are free, easy and equally / more effective.).

I’m also curious about significance to Piwik users the upcoming google changes requiring consent modes for advertising; seems likely offline conversion import would be unchanged by any of this as its whole purpose for many is privacy compliant leveraging of online data/conversions.