Close book closes Librerator if Librerator is started with opening last document
(no matter if you use Kite, Launchpad or SSH).
Edit: The following is fixed in Librerator R2, and therefore obsolete.
Spoiler:
I took another look and discovered that this one is not caused by incompatibility of Kite and Librerator. It is a feature inherited from KPV. Looking at the code, I'd say it's intentional. I don't know if it's worth fixing... personally, I don't use opening last document on Librerator start, and I doubt many people would... so, if you really want Librerator to open last file on start, have both
Librerator and
Librerator - last file if you're using Kite. If you're using Launchpad, use Shift-L-F for last file, and Shift-L-L for FileChooser (both of this only if you enabled opening last file feature using
this patch).