I’ve got two yellow Kordana minis in shallow, broad pots. Both wintered well last year by burying the pots and mounding the plants. Next to Golden Angel these were the most floriferous roses in my garden this past summer. The blooms were exhibition quality, the plants were better than most of my others with respect to disease (but I spray) and the pollen was pretty fertile too. They don’t self-set hips and I haven’t tried them as mothers but the pollen was fertile.
The Kordana roses were bred for indoor use or use in pots on balconies in temperate climates. They are not supposed to be planted out in the garden. For garden use Kordes has another line of disease resistance miniatures (the Lilliputs). Most seem to be bred from groundcover roses, so they’ll probably grow big in SoCal.