Since the URL is pretty vital for federation (users from federated instances would follow for example !main@pigedove-lemmy-clone-u9568.vm.elestio.app in order to join a community), it's probably worth getting the domain up and running before you start federating anyway. Even though it's a frustrating wait for sure!
I think there's potential for a bird instance - I've heard rumours the birdwatching community is pretty active over at Mastodon.