Another (simpler) option is that you can use https://github.com/authzed/zed to make a request with

--debug

and it'll return the dispatch count and cached count. You can see how complex the query is and if it is being cached at all that way. Fundamentally, complex queries are broken down into subproblems and dispatched to nodes that are assigned to store them in their cache. The more complex the query, the more subproblems there are.