Th e rationale for the ECJ's ruling is that the courts of member states must trust the courts of other member states to
apply jurisdictional rules correctly.
Not exact matches
Procedural
rules generally
apply only if a lawyer implicitly guarantees the content of the ghostwritten filing by signing it, unless local or
jurisdictional rules state otherwise.
Civil lawsuit trials can be conducted in a state other than the state where the breach of contract or tort giving rise to the lawsuit took place for
jurisdictional purposes and not infrequently is brought in another state, although constitutional choice of law
rules limit the circumstances under which a particular state's laws can be
applied to a particular set of circumstances in a lawsuit.)
Also, flexibility in
applying the fourth factor does not amount to
jurisdictional overreach ̶ conflict
rules vary from one jurisdiction to another.
I do not believe there would be such lacuna: the Article 34
rule applies to concurrent proceedings which are in fact in - Regulation, except international comity requires the EU to cede to foreign proceedings with a strong (typically exclusive)
jurisdictional call.