It looks like Elasticsearch is currently missing support for concurrent searching and that this is a major prospective optimization to reduce latency.

Digression: this is not the topic at hand but I personally consider the fork OpenSearch to be an historical tragedy of duplication of work and a segregation of improvements. What would be even more anti-utilitarist would be to blindly *ignore* each other advances towards making better search.

Lucene concurrent search APIs are probably among the most important feature/optimization currently not leveraged by Elasticsearch.
The fork OpenSearch has a [pull request](https://github.com/opensearch-project/OpenSearch/pull/1500) implementing support for it.

See also the [corresponding issue](https://github.com/opensearch-project/OpenSearch/issues/1286) 

I believe it would be great for end users if you could take inspiration from the PR and work on this feature.

Great blog about the Lucene feature:
https://blog.mikemccandless.com/2019/10/concurrent-query-execution-in-apache.html?m=1
See also those performance results:
https://engineeringblog.yelp.com/2021/09/nrtsearch-yelps-fast-scalable-and-cost-effective-search-engine.html
test/framework/src/main/java/org/elasticsearch/test/ESIntegTestCase.java
return getAnnotation(clazz.getSuperclass(), annotationClass);
    }
    private Scope getCurrentClusterScope() {
        return getCurrentClusterScope(this.getClass());
    }
    private static Scope getCurrentClusterScope(Class<?> clazz) {
        ClusterScope annotation = getAnnotation(clazz, ClusterScope.class);
        
        return annotation == null ? Scope.SUITE : annotation.scope();
    }
    private boolean getSupportsDedicatedMasters() {
        ClusterScope annotation = getAnnotation(this.getClass(), ClusterScope.class);
        return annotation == null ? true : annotation.supportsDedicatedMasters();
    }
    private boolean getAutoManageMasterNodes() {
        ClusterScope annotation = getAnnotation(this.getClass(), ClusterScope.class);
        return annotation == null ? true : annotation.autoManageMasterNodes();
    }
    private int getNumDataNodes() {
        ClusterScope annotation = getAnnotation(this.getClass(), ClusterScope.class);
        return annotation == null ? -1 : annotation.numDataNodes();
    }
    private int getMinNumDataNodes() {
        ClusterScope annotation = getAnnotation(this.getClass(), ClusterScope.class);
        return annotation == null || annotation.minNumDataNodes() == -1
            ? InternalTestCluster.DEFAULT_MIN_NUM_DATA_NODES
            : annotation.minNumDataNodes();
    }
    private int getMaxNumDataNodes() {
        ClusterScope annotation = getAnnotation(this.getClass(), ClusterScope.class);