I'm so glad you brought up IFS! It shows how the pathology model for the self is by no means the only valid one, because IFS believes that everyone is actually a "system" even if most people don't perceive themselves as such.

My husband has done a lot of inner work with IFS and it has done wonders for his mental health, he sees himself as composed of "aspects" like a system, but only very rarely does he have dissociative experiences now. Most of the time he's aware of the aspects and can talk about them in a way that is very self aware. From a pathological model he might be called "faking DID" even though he doesn't identify as having DID. But it's just the language of IFS is so incredibly useful and validating to his experience of life, and talking in the language of "aspects" is so helpful to me to understand him better.