There is the non-default paranoid option of disabling caches entirely. But in general the mitigation only requires isolation between sites, which doesn't have too much of an impact and shouldn't affect saving at all.

Isolation between sites is not sufficient - collaborating sites (and everyone colllaborates with e.g. Google analytics or the hundred other tracking sites) could have an ifrane that would abuse cache. You need isolation by primary site, and i don’t remember the exact issues, but there’s some obstacles over there that need addressing (and that browsers do address, but which result in the cache-hardly-ever-used situation we are in today).

Right, that's the isolation I was thinking of.

Other than jquery or google font, what does that stop from caching? Most assets only get loaded from a single site.