Username changes
Any account owner can edit their store username in the Account details tab located at: https://dashboard.snapcraft.io/dev/account/. Here is a screenshot of this page:
If the account has published any snaps, changing its username will be visible when snaps are queried (e.g. with snap info) or searched. If the account is a verified account, the account data that was used at the time of verification will not be changed.