Live-build does not have code to update LB_ISO_PREPARER in splash.svg. If you edit /usr/lib/live/build/binary_syslinux and insert -e "s|@LB_ISO_PREPARER@|${LB_ISO_PREPARER}|g" \ on line 265, it should fix this.
Live-build does not have code to update LB_ISO_PREPARER in splash.svg. If you edit /usr/lib/live/build/binary_syslinux and insert
-e "s|@LB_ISO_PREPARER@|${LB_ISO_PREPARER}|g" \
on line 265, it should fix this.