It has been said before, that when cross-federating two public categories with each other, it feels like one is sharing the same virtual place.
While subsequent changes of a post are preserved and propagated between federating systems, there are other site-specific properties which do not participate in the federation.
The wikiness of a post (“the toggle status of the wiki property”) does currently not federate between instances.
As a user of cross-federating categories, I need to be able to edit shared wiki posts, in order to contribute to the conversation.