Do a check on displayed names, not only user names (URLs)
I guess this is a very tricky one to code but it matters.
For example: if I choose "Mister Test" and all the account names are free (such as twitter.com/MisterTest www.MisterTest.com etc.) but there is still a musician called Mister Test on Spotify, or a Youtube User called Mister Test (with another User ID), then it might still not be practical to register the name.

Hi Rutger,
While I agree that this may be worthwhile, it’d be tough to achieve using Namevine’s update-as-you-type system.
Also, my feeling is that whoever has the actual vanity URL/username stands a better chance at branding more effectively on whatever social media platform they’re using.
However, I’d like to understand your use case a little better so I’ll follow up with an email shortly.
Mike / Namevine