The CJEU held yesterday in C-20/21 LOT Polish Airlines, on the place of performance (hence creation of jurisdiction in an application for flightdelay compensation) of a flight consisting of a confirmed single booking and performed in several legs by two separate air carriers. That the claim came within Article 7(1)’s gateway for contracts is a result of CJEU flightright. The Court also held in that case that both the place of departure of the first leg of the journey and the place of arrival of the last leg of the journey were forum contractus.
In the case at issue, jurisdiction is sought for the place of landing of the first leg of the journey. In CJEU Zurich Insurance, on multimodal transport, place of dispatch was added as forum contractus, with the CJEU refraining from holding explicitly whether other legs of the journey could count as such forum (Tanchev AG had opined they should not). In current case, the CJEU would seem to confirm my feeling that in Zurich Insurance it implicitly sided with a limitation of fora. Indeed it holds that the place of arrival of the first leg is not forum contractus under A7(1), however, there is a caveat: :
the referring court does not indicate the elements of the contract which could justify, with a view to the efficacious conduct of proceedings, the existence of a sufficiently close link between the facts of the dispute in the main proceedings and its jurisdiction.
The CJEU’s dictum is formulated in more absolute terms:
The second indent of [A7(1) BIa] must be interpreted as meaning that, in respect of a flight consisting of a confirmed single booking for the entire journey and divided into two or more legs on which transport is performed by separate air carriers, where a claim for compensation, brought [under the flightdelay Regulation 261/2004] arises exclusively from a delay of the first leg of the journey caused by a late departure and is brought against the air carrier operating that first leg, the place of arrival for that first leg may not be classified as a ‘place of performance’ within the meaning of that provision
However given the caveat  it is not to be excluded that contractual terms could distinguish the finding of lack of forum contractus.
EU Private International Law, 3rd ed. 2021, 2.399 ff.