I know it is for identification, except for rare cases, in fact few weeks ago I updated NIP-05 to clarify that.
And that is precisely why there is no point in showing it everywhere, especially if it is invalid. The point is to simplify the interface (I know, I won you over here, haha) and avoid exposing a detail that is unnecessary and may indeed be confusing.
Intead in the profile, with a proper explanation, it can be useful to debug misconfigurations or have a clearer idea about what the profile is trying to do.
What is this impersonator tag?