Just a thought: Maybe that 'flipping back and forth' can be a part of what it is describing. Like... maybe at times you experience the fragment parts and so think "yes, this describes what it happening to me!" but at other times you are dissociated from the experience of those fragment parts and so don't feel it applies to you at all.
Our old hosty ones felt the same way about the DID diagnosis. When the evidence was staring them in the face or they managed to connect to some of the trauma of the inside ones they felt it was real. At other times they needed to deny it.