Default UI setup for chars

I have multiple accounts, and I just cleared all settings to resolve a bug.

I know how to copy a char/account settings DAT file, but it’s still a tedious process. Is there a way to alter to the default? I tried changing the “core_char__.dat” and “core_user__.dat” but that didn’t work.

As I login my accounts, the new settings files are created, so I wonder what the template is created from. Anyone know?