The thing about best practice is that the uninitiated aren’t familiar. It’s borderline ivory tower stuff to create friction when posting in the context of the above. Remember that the relative ease of the standard install is such that sometimes installing Discourse might be a users first ‘sysadmin’-type task.
We can’t possibly go about verifying domain ownership before someone posts a link. If they share a config with an invalid domain how do we differentiate between a typo, improperly configured DNS, and a domain which has yet to replicate?