Problem Definition

Currently, when verifying a domain under your Organization the verification process doesn't check if this domain hasn't been verified by another Organization already which results in the domain being verified in the current Org while leaving it superseded in the other.

As all site-admins can create an Org this can likely generate confusion within companies.

Suggested Solution

Implement a constraint that checks if the domain is already verified and in case it is, prompts to the user a warning message and does not complete the action.