I'm no expert but I've been diagnosed with schizoaffective disorder and I also have synaesthesia and aphantasia. I don't want to alarm you but I would just like to briefly share my story. At age 20 I started hearing voices in my head. These voices came about while I was smoking marijauna because of clinical depression and anxiety and at first the voices pretended to be angels. Then the voices turned on me and started saying "ki** yourself". I did not want to say anything at first but then I was persuaded to go to a mental institution. I got out and the voices kept saying the same thing. I eventually crashed a car into another in an attempted suicide. Now I experience phantom smells, phantom sounds, sensations all over my body like someone is poking me all over, headaches, but no visual hallucinations. I've been in and out of mental institutions and I see a therapist monthly. I'm fine now. Long story short, I don't remember anything in detail. I'm just aware that everything happened so yes the aphantasia does protect me and may potentially protect others from severe trauma because after it all, I don't have PTSD. I hope this helps. :)