Very well explained by Rellwood the option with comma
But it is more automatic as explained in
https://github.com/kiwidude68/calibe...custom-columns
As intended by kiwidude the plugin collects the data and puts it first in the identifiers field and then in each custom column.
And the truth is that in goodreads the rating number is with a point.
But everyone can choose how to do it and here is the other option.