Automatically replace [[a/b/c]] with [c]([[a/b/c]])?

Just in case you give up on namespaces, here there is an alternative method to organize pages hierarchically that has worked very well for me, with no downsides at the moment.

Namespaces are more to disambiguate pages as I explained here.

So far the best use I have found for namespaces is adding multiple tags at once. For example #person/author also adds #person.