Thoughts: The requirement of apps to have a publicly accessible website conforming to the IndieAuth API might be a limiting factor
On the other hand, globally unique identifiable apps is a huge benefit in terms of admins being able to restrict app access. I.e., currently every user can revoke app access to their account, but server admins cannot say "I don't want the cross-poster to work with my server" because there is no such thing as *the* cross-poster
