I use we, us, they freely in my journal and in the presence of my counselor.
I work very easily with IFS dynamics and it feels completely natural to refer to myself/my other parts in that way.
It does feel validating to my parts and it feels comforting to them that they are acknowledged.
I don’t think that will ever “go away” and not be “them” with integration and the process of us all learning to work together.
I really feel like it’s progress to give them that validation and importance of acknowledging that they are “they”, “us” and “them”.
I think in some form or shape, everyone has “parts” and it would be beneficial to acknowledge them that way.
ETA: I do not bring my parts out with other people. I think of the verse in Proverbs that talks about not throwing your pearls to swine and would not want to dishonor my parts in that way.