The KoboUtilities-Plugin has a new feature to add metadata to the book details.
If you have the page or word count in Calibre, you can add it to the book details, which can be read without opening the book.
The feature is still in beta, but for me it works very good.
See
https://www.mobileread.com/forums/sho...postcount=1017
for the first version.
Here is an update that allows a different definition of the template.