More to the point, emacs-w3m does not have a cache at all. That's the real thing to take away -- that images are not the issue, the cache is the issue, and the

More to the point, emacs-w3m does not have a cache at all. That's the real thing to take away -- that images are not the issue, the cache is the issue, and there are lots of things that can go into a cache beyond just images. If you're not caching anything, you could probably load images by default and you'd still be fine.