Client-Side Error Needed: SP SSO Descriptor Information page for duplicate NameID Format

Tested in version 1.5.0-SNAPSHOT-8f3e0e8
Description
When user selects a duplicate NameID Format to send, the Next button is dimmed. However, there is no other client-side indication of what is preventing the user from moving to the next page.
 
Steps # Log into UI

1. Click 'Add New' button and select ‘Metadata Source'
2. Move through the application to the 4. SP SSO Descriptor Information page (and 8. Relying Party Overrides for the 'NameID Format to Send'  and 'Authentication Methods to Use' selection)
3. Click the Add button for 'NameID Format to Send' twice
4. In both of the dropdowns, make the same selection. Ex: urn:oasis:names:tc:SAML:1.1:nameid-format:unspecified

 
What is occurring
When the first one is selected the Next button is enabled. When the second one is selected, the Next button becomes disabled but there is no client-side validation to indicate what the user must do to resolve the issue.
 
What is expected
When a conflict is created by the user, an error will tell them what is needed to resolve it.
 
Screenshot