I'm not sure where else to report this...

All throughout the website, you give examples of how to perform various operations related to search but the examples are GET requests with a data body.

This is wrong according to the Http 1.1 spec that dictates the body of a GET request should not change the response contents. In other words, you should be able to ignore the request body and get the same result.

As an alternative, you should document the query string parameters better. For example, it's not documented how to do highlighting with query string parameters, only a GET payload.

Ultimately, calling GET with a payload should be deprecated and removed from future releases of ES. This is not recommended by anyone and I can find no support for doing things this way.