I believe you must have misread what you quoted, because whatever point you're trying doesn't really follow what you quoted. They let you configure the number

I believe you must have misread what you quoted, because whatever point you're trying doesn't really follow what you quoted. They let you configure the number of expected results to cache for a given query, the number of cache results are configurable based on your use-case for the results (e.g. if your website only lists 100 results, don't store beyond that). If more results than that for a given query are returned then they disregard additional results since you told it you won't make use of them. In essence, they're saving you from caching results that you'll never consume. How you got from this to "just use /dev/null" is a mystery to me. It has to be a misread or misunderstanding.