Hello the_Pan and thank you for your answer which also allowed me to realize that I had forgotten to configure the forum to receive response notifications
In fact, on my first try, I had chosen "No" as default value.
And now, for my 3rd test, I have left the field empty, which gives an undefined value.
The result is still the same: nothing is automatically written in the new column
I also tried what you suggested: to mark a book that I knew I had not read with "yes" on Calibre. I then unplugged my e-reader and went to see if the book appeared as read on Vivlio but no
I can try again with "No" but it actually bothers me a bit. I have over 350 books in my library, many of which I have already read. It would be very annoying if I had to redo everything by hand afterwards...
What do you think?