The documentation states:
“Caching. We recommend that you cache API responses in your application or on your site if you expect high-volume usage. For example, don’t try to call the Twitter API on every page load of your hugely popular website. Instead, call our API once a minute and save the response to your local server, displaying your cached version on your site. Refer to the Terms of Service for specific information about caching limitations.”
In the Terms of Service, the only reference to caching limitations is in regards to geolocation data.
What are the caching limitations, if any, for public tweets? i.e. caching duration, deleted tweets