Going back to the original question on this thread -- is it possible you could credit the flight to JAL's own mileage program retroactively? Not sure if it's that many miles or if you could use them for something or transfer them out but perhaps worth a try?

https://www.jal.co.jp/jp/en/inter/boarding/codeshare/

"Mileage accumulation for codeshare flights
Mileage will be accumulated when you book and fly under JL flight number, except for the codeshare operated by JMB partner carrier.
Please confirm at reservation, you are booked with JL flight number."