[Khoas]

It is true that VFT cultivars do not breed true. Certain traits can breed through namely colouration and size. I have grown several plants from seeds produce through crossing cultivars and while the seedling usually are different from the cultivar, a few will be quite close to the form of the orginal.
One exception, in my option, is Royal Red. There is evidence this actually a variety which came from a wild population. My limited experenice with seedling of Royal Red it does breed true.