I am NRT now. I have never flown JAL before today (flew LAX-NRT on AA, onward today on JAL). I printed my own BP at home, 2 days ago, not knowing that the system was new. Worked fine for luggage (they just scanned my BP, printed bag tags, didn't give me new BP). Then, at Sakura, scanned my BP again. So the self-printed BP seems to work just fine.