[gingerbeardman]

The SETUP volume mounting annoys me for a couple of reasons:

1. calibre does not eject it
2. I do not want to use the setup files.

I found my own solution, on macOS X, to prevent the SETUP partition from mounting:

$ diskutil info /Volumes/SETUP

This gives us the UUID of the volume we are interested in, ready for the next part

$ sudo pico /etc/fstab

UUID=5B7F482A-CBB1-371D-9739-7823473EEA35 none msdos ro,noauto

To save the file press Control+X, then press Y, and then press Enter to confirm.

$ sudo automount -vc

This refreshes the automount settings.

Voila, no more SETUP mounting when you plug in the reader.