I also have a 4n plant that have lots of problems with flowers....but sometimes give spectacular perfect flowers(usually 1 or 2 maximum each flowering).
That's pretty typical of Eric Young 4N progeny to show the notching on the petals. I have some lovely Magdalene Rose plants, that grow and bloom great but have such deformities most of the time. They range from normal to pretty bad. Putting besseae onto such plants will usually fix the problem in the next generation.