hoping to have understood your question, here, I added this section to /etc/slackpkg/blacklist
Code:
# alien's kde
PyQt
QScintilla
akonadi
attica
ebook-tools
hunspell
k3b
kaudiocreator
kde-l10n-it
kdeaccessibility
kdeadmin
kdeartwork
kdebase
kdebase-runtime
kdebase-workspace
kdebindings
kdeedu
kdegames
kdegraphics
kdelibs
kdemultimedia
kdenetwork
kdepim
kdepim-runtime
kdepimlibs
kdeplasma-addons
kdesdk
kdetoys
kdeutils
kdevelop
kdevplatform
kdewebdev
konq-plugins
libdbusmenu-qt
oxygen-icons
polkit-qt-1
skanlite
sip
soprano
system-config-printer
virtuoso-ose
shared-desktop-ontologies
phonon
slackpkg install-new shouldn't show anything from the kde in slackware, but slackpkg upgrade-all will if you don't blacklist them.