oops, so sorry, you are right!
So you need to take the card out of JeVois and attach it to a computer. You should see the BOOT partition (either with its name under Linux or MacOS, or, on Windows, it will be the only flash disk that appears). Contents are:
Then using notepad or similar, save an empty file named 'quietcmd' on that disk. Properly eject it and the file should be there now.
Or try this (we have tested it now) in the Inventor console:
shell mount -o remount,rw /boot
shell touch /boot/quietcmd
shell mount -o remount,ro /boot