Not that I’m aware of since it’s not actually a type of script, but more using data that’s available within the client to create a new interface option. So a restriction wouldn’t be to block nametags, but would instead need to block scripts from accessing the avatar list information.
Even if you could block scripts from accessing the avatar list in a particular domain, if someone really wanted to cheat they could recompile the interface to remove the restriction. Since you can’t get away from the interface receiving the avatar information as it needs to render then.
When it comes to gaming you’d have to really on the trust model, and trust the players to play fair.