Federated Search API - Add "Get" Method

We are working on loading a bunch of content into the Federated Search. We are running into an issue with stale content in the community index. I know we can just clear the whole thing, but it takes a while to reload the whole index via API. I would be amazing if there was a GET so we could pull the whole index down and compare it against the current data we have and then delete the stale ones if they are not in the current list.