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
@Override
        public List<TransportInterceptor> getTransportInterceptors(
            NamedWriteableRegistry namedWriteableRegistry,
            ThreadContext threadContext
        ) {
            return Arrays.asList(new TransportInterceptor() {
                @Override
                public <T extends TransportRequest> TransportRequestHandler<T> interceptHandler(
                    String action,
                    Executor executor,
                    boolean forceExecution,
                    TransportRequestHandler<T> actualHandler
                ) {
                    if (TransportService.isValidActionName(action) == false) {
                        throw new IllegalArgumentException(
                            "invalid action name [" + action + "] must start with one of: " + TransportService.VALID_ACTION_PREFIXES
                        );
                    }
                    return actualHandler;
                }
            });
        }
    }
    /**
     * Returns path to a random directory that can be used to create a temporary file system repo
     */
    public static Path randomRepoPath() {
        if (currentCluster instanceof InternalTestCluster) {