LT,
From your Dear T post: I think it is growth. L says new things, even things we perceive as "negative", is growth. For example: the first time I admitted I was angry with her. Or now we joke (but it's serious/honest) if I slammed a door or canceled a session, that would be growth too.
Embracing "negatives" is growth. A lot of us try so hard to be "good", but the truth is, we're not ALL good. We have anger and jealousy, etc. And we all have different parts of us. It's part of being human. So you feeling comfortable with irritated or frustrated parts of you is a good thing. At least imo.