Question about in-game Names (game pass vs. steam)

So my in-game name is SpaceCat6842 and I really hate the 4 numbers at the end of my name. I even made a new account with a unique ID so I don’t have to have those stupid 4 numbers–I know it seems silly but for whatever reason it drives me a bit crazy.

If I get the steam version, can I just be SpaceCat even though there are a million other SpaceCats out there?

Also, with the steam version can you change your name freely (instead of paying 9.99 which you have to do on Xbox).