Maybe for a fee, you could be able to have a rebranding. Changing your username. Rebranding isn’t only about new logos in your services or changing visually gigs.
This is a win-win.
Fiverr wins more money from people who wish to change their username and sellers (I can’t see buyers doing this) are happy that can rebrand themselves with a brand new username.
If this is a headache to the Fiverr team, maybe make it limited to a one-time-only change allowed.
Fiverr - In doers we trust