As my T explained it to me, schizoaffective is more toward schizophrenia than it is a mood disorder. So I took it to mean that schizoaffective is more like having schizophrenia AND BP or depression, but more schizophrenia symptoms than the mood symptoms. Bipolar w/psychosis is just bipolar.
I know you've been concerned about this. Maybe you can track the times you have psychosis and how your mood is when it occurs. You could keep a basic mood chart to see if and how your moods fluctuate. Take notes on the chart where you have a psychotic episode. I don't know if it will help or not because I don't have psychotic features. But I'm hoping that you find your answer. I know how you feel in that respect.
Good luck