It is still in at the dealer’s.
JLR CRC rang me around lunch time to tell me all should be done later today having spoken to the dealer.
I rang the dealer at 15:30, and after a little to-and-fro got called back by the service manager. Basic result is, can they heep it until Monday? Road test showed the air con was blowing hot air. They confirmed this both with their own probe, and with mine which I had left in the car.
The tracking application does now seem to connect to he vehicle.
My contact at JLR is on holiday for two weeks from Monday, so we will see how we go on next week.