Personally, I don't mind reading back and forth threads between two people. Sometimes I might not post if I don't want to throw them off, but I still want to read what they have to say.
I don't know if this will confuse it further, but alter voices sound like they come from the same place in my head that my own thoughts come from, in terms of how they feel and the resonance inside my head, but they don't sound like my own internal voice. They sound like they originate from the same place, but they are different.
...in re-reading that I'm not sure it will make sense, but maybe it will.
Are you and your T still trying to define whether or not you have DID? Or are you deciding on treatment plans?