It's no more supported than Librerator, but it looks like you should be able to change it in the launchpad/kpdf.ini file.
Code:
[Actions]
# start kindlepdfviewer with filebrowser in /mnt/us/documents
P D = !/mnt/us/kindlepdfviewer/kpdf.sh /mnt/us/documents
# start kindlepdfviewer with last document
P P = !/mnt/us/kindlepdfviewer/kpdf.sh
# start kindlepdfviewer without framework in /mnt/us/documents
P K = !/mnt/us/kindlepdfviewer/kpdf.sh --framework_stop /mnt/us/documents
# start kindlepdfviewer without framework on last read document
P L = !/mnt/us/kindlepdfviewer/kpdf.sh --framework_stop
# restart amazon framework - when it got irritated
P R = !/etc/init.d/framework restart