I like that I can lock my account using SMS-based multi-factor authentication. However, this would be much more useful if you could use it to lock down nameserver settings, not just to prevent the domain from being transferred.
Preventing domain theft is high priority, but a hacker could do great damage by changing a domain's name servers since changing them back could take up to 48 hours due to DNS caching.
I doubt this would inconvenience many users since nameservers very rarely need to be changed for most domains. Perhaps it could be made an option to appease users who'd prefer multi-factor authentication just be used for account settings and domain locking.