(1) Reduced the debouncing duration so that the final element can be rendered asap after visible.
- If the user is scrolling non-stop, it would continue to debounce and the GUI ends up not showing the final element.
- 25ms seems enough to prevent the initial false-positive that occurs in the scenario of "adjacent/upper elements resized late, so our element was briefly on screen when mounted". If not enough, we can make this a parameter.
(2) Removed `lastUpdateDate` that was a quick hack for Recommended section. We don't use it on that element anymore, so remove the hack to keep the file clean.
524370711c