Of first note is that the CJEU unlike the AG does address the Article 24(5) Brussels Ia issue of exclusive jurisdiction for claims in ‘enforcement’ of a judgment. It holds that an action for restitution based on unjust enrichment does not come within A24(5)’s scope for  an action the subject matter of which is a claim for restitution based on unjust enrichment is not intended to obtain a decision in proceedings relating to recourse to force, constraint or distrain on movable or immovable property in order to ensure the effective implementation of a judgment or authentic instrument. This is the case even if that unjust enrichment arises from the fact that enforcement has been annulled.
On the A7(1)-(2) issue the Court first of all and justifiably dismisses the suggestion made ia by the European Commission that A7(1) and (2) BIa dovetail: ie that necessarily a claim which is not a contractual one, must (and in subsidiary fashion) be on in delict per A7(2): : forum delicti requires a harmful event (reference in support is made to Austro-Mechana), which is simply absent in cases of unjust enrichment.
A claim in restitution of unjust enrichment may in fact be contractual  if there is a pre-existing relationship that is closely linked to the claim. An obvious example  is that of the applicant relying as the basis of its right to restitution. on unjust enrichment closely linked to a contractual obligation which he or she regards as invalid, and which has not been performed by the defendant, or which the applicant considers he or she itself has ‘over-performed’.
EU Private International Law, 3rd ed. 2021, 2.419 ff.