Interesting to see them mention tulpas here. It's always been a bit of a meme online, but I knew a pretty tenured hypnotist who was utterly terrified of the things. He'd seen tulpas cause irreversible psychological damage to the people who adopted them, where many people would become completely attached to a character or particular fiction in their head. This could cause them to act out involuntarily, induce constant…
Accessing these voices is invaluable for writing fiction, perhaps the difference with a tulpa is the level of reality and influence ascribed to a single 'not-me' voice?
I also see the ability to have an internal Socratic dialogue as requiring a kind of ego-splitting, in a way that could be conceptualized as a tulpa asking (often surprising) questions.
Very abstract and hard to talk about stuff, I hope that makes sense.