A strong use case for this would be to assess how people are interacting with the cancel/update link in the TY autoresponder:

Linking relevant phab from @SHust T404918: Request Open Rate Data for CiviCRM Emails

Please keep this in mind.

Open rate data is subject to consent in several jurisdictions. Safety has a task to address permission requirements: https://app.asana.com/1/3758245663860/project/1211094604436364/task/1213378848966558?focus=true

EU data protection authorities (e.g., France’s CNIL) have issued consultations or draft recommendations that tracking pixels/cookies in email for open-rate tracking require separate explicit consent and are treated similarly to cookies under ePrivacy/GDPR norms. https://www.getmailbird.com/eu-digital-consent-email-tracking-requirements