I see where your getting at. IMO, have a distinctive or recognizable style is much better than having recognizable attire. I don't like it when a character is locked in a particular attire because they won't be "themselves" without it. The slightest altercation to said outfit will make fans bust out the torches and pitchforks. I have no trouble recognizable her in her civvies as no other hero has her style among the X-Men or other heroes. The other character I can think of that's similar is Nico from Runaways and it's still very different.
You hit the nail when it comes to her physical features. From looking at other X-23 pics there's nothing that stuck. I really like the hair antennas. If that artist gets the chance to draw her more and maybe also do interiors that mark could stick.
He hasn't used the Power Man name in years. Being black is all he needs. It was good enough for him to lead the Avengers and have Squirrel Girl has a babysitter.