In Epic 1.5, item (3) is about "Briefly cacheable search results". Is that caching on the API side, or in the browser?
Also, has there been any discussion about how to determine the number of items to cache and the time to cache them? (This seems relevant to a browser-side cache.) It should be possible to capture some of the logs for people typing in the search box to get a sense of how far they tend to back up and how long it takes—though not every keystroke is in the log because some people type too darn fast.