I tried putting the URL into the search but nothing returns
I think the proper behavior would be that two instances are federated, a user would be able to see all communities in both.
It’s going to be especially hard for users on a small instance to find content if they, or some other person on that instance, has to search for it first.
If I type “!coffeeaddicts” into the search bar, it should show all communities in all instances that are federated with my own that match that query. A person running their own instance would have to search every single community and wait however long for it to populate.