Our grown up kids were on a separate PNR to us on a trip to SOU-AGP. Outbound Flight cancelled my wife and I were rerouted via LGW and kids LHR. Apart from sorting out logistics at short notice , not an issue as they are adults. However as I thought there was a good chance of another flight cancellation on the return I phoned up to link the bookings , The Agent did this but was adamant it wouldn’t have stopped us being re routed on sep airports on the outbound nor would it prevent it on the return. All silver and in CE if that makes a difference. So just a word of caution on the sep PNR route.