I am afraid we cannot control this since it comes and serves from Cloudflare’s servers.
I’d ignore the suggestion from this online tool up for now as if the Cloudflare changes the code, it would apply to millions of Websites and customers using this, therefrom if the Rocket Loader file is kept for 2 days in someone’s Web browser for 2 days, that’s a quick “flush” to get new code working, rather than keeping the file with non-functioning code for a year or longer, or waiting for your Website visitor to manually clear their cache in their Web browser to fix something, a question is also if they know how to do it or not, which is not quite good solution, of course if there is some issue then it has to be resolved as quickly as possible. Just an example of a case for 2 days cache.