At the moment I don't see why we should make such a cache here. For the first config var of a request, the cache has to be established first, that means every config var has to be written into the cache-object. Of cause, for the second config var, the signal hasn't to be send again, but for this the whole cache (dict) has to be read again.

And a developer has to pay attention about this cache. That's why I don't like it.