> if the updates fit on a single floppy or a stack of 20 floppies
The display says "INSERT DISK #1" so probably at least two, and it looks like there's a place for maybe a dozen under the "diskette stowage latch":
https://regmedia.co.uk/2020/08/10/b744navdatafloppydrive.jpg
https://twitter.com/harrymccracken/status/940263706444754945...