First extending yum's exclude setting with packages excluded from the
compose in the kickstart package manifest helps in group selection (see
also #456882), since @core has a mandatory package called
"fedora-logos". Although livecd-tools already removes the packages
(after package and group selection) in the excluded list, I think this
is cleaner as not even dependency resolving will know about the package
explicitly excluded (and the package is thus not pulled in accidently,
afterwards).
Kind regards,
Jeroen van Meeuwen
-kanarip