That's what we ended up doing for our migrations. We actually had a bunch of old Elasticsearch 2.3 databases (ancient), so we stood up an OpenSearch database in

That's what we ended up doing for our migrations. We actually had a bunch of old Elasticsearch 2.3 databases (ancient), so we stood up an OpenSearch database in parallel for each and on service startup did a one-time automatic index and bulk copy over of all the data. So far very happy with OpenSearch.