Hello. One of the fedora calibre maintainers here.
I'd be happy to improve the packaging in fedora. In this case there are very good reasons not to ship the calibre-mount-helper however. Our desktops automatically mount mass storage devices when attached. A mount-helper would just mount them a second time or otherwise confuse things and be an unneeded step.
I've pushed an updated package for testing, so please do test and let me know if it works for you.