It was told to me, that cdrkit is more or less dead and won't be shipped in the next but one. So it would be good, if k3b would support other tools like xorriso or libburnia. Debian bugreport: https://bugs.debian.org/982221
You may want to blog or spread the word a bit more about this, there's really no maintainer for k3b at the moment, i do some low level bugfixing, but that's totally out of scope for my involvement