I can’t get mine to get to bootloader mode at the moment. Followed the instructions to the letter, but when I turn my case on all the outputs are dancing away like normal, no slow pulse on 6n. Hmm…
edit - I managed to resolve this by turning the case on once set to shape and cycle, turning off again, and resetting shape to sound. The same with both my JFs. Had no issues updating whilst playing back the update from Live at 3/4 volume, with a patch cable from the headphone jack of a laptop