Same old shit but a different day
Yes, it is possible to change your username; however, there are some standards. Visit this thread for more information on it. https://www.smogon.com/forums/threads/new-new-name-and-profile-change-requests-read-the-op.3609246/I'm unsure if this has been answered already, but I'll ask anyway just for assurance sake.
Is it possible to change your username at all on the forums? I'm a bit iffy on still using my current one given how it's grown a bit dated since I first joined, and I'd prefer not to outright make a new account given how there is history to my account (despite it not being as much as with others).