(It's a particular approach to privacy whereby for sites I don't visit that often or log into, disabling cache prevents them from knowing whether I have visited their site at any time before, or another one that has cross-site objects loading, either.)
However, I've come to see that sometimes, it's more in my privacy interests to have any cross-site objects that I use a lot, to be SAVED in cache, so that after the first download so I am not re-pinging (to re-download) those objects every time I browse other websites referencing them, thus announcing to that third-party website every page that I'm visiting on the web when using it.
So I am in need, of a way to control what is cached, and what isn't, in Firefox.
Is there some add-on that can do essentially do rule-based 'firefox cache control', or to put it another way, a rules-based 'firefox cache blocker'?
I can find add-ons that do the opposite - custom exceptions to (the normal) 'caching allowed' by BLOCKING caching for individual sites - but not the other way - ALLOWING cache, for ONLY certain sites (or URLs) where the default is to not store cache.