I think I've found a bug. On my install, when browsing either the user directory or ranking, the Ajax requests make no difference as all data remains static from cache. Pressing F5 in the browser renders nothing more than a large output of JSON instead of the intended page.
Disable the cache and everything returns to normal again. File based caching, not redis.
Have had to disable the extension for the time being. Similarly, I've conducted some speed tests with cloudflare enabled, recache enabled etc, but have to admit, I'm not seeing a huge difference in speed apart from a reduction in TTFB with cloudflare disabled. With cloudflare enabled, it doesn't seem to make much difference to the loading times of my flarum with recache enabled or not.