Not sure what are you refering to but if I am correct in understanding you want to change the behaviour based on your custom logic, this can be done by implementing EditorDescriptor and overriding the ModifyMetadata method. 
Regards
/K

Well, I see the name property in PageData class. Currently you're allowed to change it per language. In my case, it should only be editable in en-US.

Can you please point me in the right direction?

This is pseudo code, it should work

public class CustomMetaDataExtender : IMetadataExtender
    {
        public void ModifyMetadata(ExtendedMetadata metadata, IEnumerable<Attribute> attributes)
        {
// loop through metaData.Properties and if its Name and langue is not en-us then 
foreach (ExtendedMetadata property in metadata.Properties)
        {
            if (property.PropertyName == "Name" and current language is not en-us)
{
property.disabled = trrue
}
}

        }
    }