It should operate how the judicial systems operate in Anglo-related countries. The US SCOTUS has used legal rulings from the UK and vice versa as "guidance" to their own legal rulings, but not as authoritative. The FAA/EASA/ATSB/* should refer to each other.
A nitpick: the usual term is "persuasive", as in "we find the argument of our brother court to be persuasive". This typically means that the foreign case does, in fact, become precedent by proxy.
For example, as an Australian law student, I read Marbury v. Madison, which was held persuasive in Australia because of the direct influence between the US constitution and Australian constitution. Another case with enormous worldwide effect is Donoghue v Stevenson, which was the beginning of modern Torts law.
EASA tended to certify on the same day as the FAA. FAA tended to certify a month or two after FAA. Now EASA no longer trusts FAA like FAA didn't quite trust EASA.
Do you think it should be the other way around in tit-for-tat political reasons? Or because "Many eyes makes all bugs shallow" or some other reason?