DPMA Extension Digit Limit

Playing around trying to setup some Digium Phones with DPMA and the plan was to use 10 digit extensions in Asterisk but when you create the 10 digit extensions, only one extension shows up under Connectivity > Digium Phones. If you look in the actual conf file at /etc/askterisk/res_digium_phone_devices.conf you will see 1 phone type entry that with the heading that doesn’t match the extension number.

I further tested 8 and 9 digit numbers and they seem to work properly and add an entry for every extension.

Is this an oversite in coding, a bug, or intentional design? Anyone?

Thanks in advance.