Q. Will there be any public interface for the end customer where they will be able to check the status of their DPML ?
A. The whois output at "http://whois.donuts.co/" is public and can be accessed by anyone. If you search Whois for your trademark and any valid Donuts Registry TLD it will inform you that the label is subject to a DPML block.
For example if you search for "yourtrademark.camera" you will receive the following notice.
"This domain name is not registered. It is blocked from registration as a domain name.This string is a trademark.If you have an exact match trademark for this string, it may be available for registration."