Usually when I want to do this, I just create 2 stores for a given
category. Scribe will then forward to both of them.
<store>
category=foo
...
</store>
<store>
category=foo
...
</store>
The only caveat is that this currently doesn't work for prefix stores
(ie category names that end in a wildcard *) or the 'default'
store.
In these cases, you would need to use a multistore.
-Anthony