Package module and cache updates

When using the package module, how can I make sure the cache has been updated? It would seem that state: latest implies a cache refresh; but it doesn’t seem to actually be the case from my testing.

Is there a way to instruct the package module to refresh the cache? If not, is the only solution to use the distro’s package manager module to do it, defeating the purpose of an isomorphic package module?

package serves the 'lowest common denominator' and does not deal with
specific features of each packager, it does not defeat the purpose, it
is just of limited use.

The same way it cannot 'autotranslate' package names across
versions/os/distros, it cannot deal with the different ways package
managers deal with their repos.