[mistwang]

But that controls the browser cache, doesn't it?

No, it control the server cache behavior.

You can configure LSWS to use cached page by default, and turn off cache with rewrite rule when a page should not be cached.

Maybe it is not exactly what you want, I think we probably need to add a special "Cache-control" directive to tell LSWS when to update a cached page with new content.