Hi, it would be great if this became a standard feature in HubSpot!
We have implemented a new parameter (GDPR Last activity date), a date that is updated based on the latest activity of a Contact (there are a few different parameters you can check). Based on your retention period, how long you decided to save contacts according to consent, we compare this with the GDPR Last activity date. If the contact needs to be deleted we send an email to the Contact Owner for deletion.