Test cluster with high OIDs above the signed-int limit (2B+)

Hi. A few weeks ago, one of our clusters, with high DDL churn from
UTs, crossed the 2B mark for OIDs, which exposed a bug in our code.
I'm moving into creating clusters on-the-fly for testing, and would
like to force that situation to avoid a future silent regression,
since it takes a long time to cross that threshold, and we do move up
in major versions, so the over-the-threshold cluster will be
abandoned. How can I achieve that? A quick AI query yielded nothing,
but this is unusual enough that there's little to no material to have
good answers. Can PostgreSQL experts/hackers weigh in on this please?
If not possible now, can this be supported in the future please? --DD