Details and application of Article 11
Definition : Article 11 of Regulation n° 650/2012
Where no court of a Member State has jurisdiction pursuant to other provisions of this Regulation, the courts of a Member State may, on an exceptional basis, rule on the succession if proceedings cannot reasonably be brought or conducted or would be impossible in a third State with which the case is closely connected.
The case must have a sufficient connection with the Member State of the court seised.
Even supposing that a French court does have jurisdiction pursuant to Article 11, in principle a French notary should not need to issue an ECS on such grounds.