Is your feature request related to a problem? Please describe.
The current opensearch integration does not support routing. Using routing can bring better performance and memory optimizations.
In cases, important in knn indexes to avoid overprovisioning a cluster with too much resources just because data is not properly routed across shards.

Describe the solution you'd like
Add support for writing in opensearch operations (write, deletes...)

Describe alternatives you've considered
Is there a way of using it which I was not aware?