Behance project ID stability during Adobe ID migration for portfolio synchronization

Context

A small application synchronizes Behance portfolio data into a local store and must migrate to a new backend without downtime. The migration plan relies on stable project identifiers to deduplicate records across incremental sync runs.

Constraint

The Behance REST API v2 returns a numeric id field for each project, but documentation and community reports indicate this identifier is not guaranteed to remain stable when a user's Adobe ID changes — for example, during an individual-to-enterprise Creative Cloud migration or Adobe ID merge. No alternative stable key (such as a UUID or content hash) is exposed by the API.

Unresolved behavior

Without a reliable primary key, the migration tooling cannot safely determine whether a project returned in a later poll represents the same creative work or a new entry, risking duplicate records or data loss during the cutover window.

What strategy can ensure accurate deduplication when the only available identifier may change during an Adobe ID migration?
Is there an undocumented field or combination of fields (e.g., created_on plus owner.id) that remains invariant across identity transitions?
Can the API be queried in a way that surfaces the Adobe ID linkage to correlate pre- and post-migration project records?