Concepts
Plan history and retention
How much history a plan shows
retentionDays in GET /v1/workspaces/{workspaceId}/entitlements is how many days of responses the workspace's plan shows.
Responses older than that are left out everywhere. That means lists, exports, single reads and webhook delivery logs, since a delivery carries a response. They're kept, not deleted, and they come back on a plan that shows them.
Deleting hidden responses
DELETE /v1/submissions/{submissionId} works on hidden responses too, so an erasure request can always be honoured.