Yes, I think sometimes dissociation doesn't work for dissociation issues but I also read it should be safe for trauma. Although I've only read about using it for simple trauma, like accidents, phobias of specific things (snakes, flying) or victims of crimes. So far I haven't found a mention of using it for more complicated long term issues.

However I do have something that may be used. It's a memory of an incredibly stressful year when I was a victim of bullying at work for one year and I had all the symptoms of acute PTSD (nightmares, insomnia, hypervigilance,...) maybe I could treat this memory as a single event with a starting and ending point and treat it as a simple trauma using this technique.