Child's first passport supporting documents

What supporting documents do you normally need to provide for a child’s first passport if the child is born overseas?

I applied for my daughter’s first passport 4 months ago, and I’m beginning to get more that a little frustrated at the time it is taking to process.
My daughter was born in the Philippines, her mother is Filipino and I’m a British Citizen.
I live in the UK and my partner and daughter are residing in the Philippines

So far I have had to provide:
Mothers CENOMAR
Full copies of Both Passports
Daughters MN1
Daughter’s Birth Certificate
My Partners and I birth certificates
My Driving License
Hospital Records relating to the birth including invoices, scans etc.
Family Photo’s

They now require a PSA certificate (Philippines statistics authority)
My understanding is this won’t be available until my daughter is 6 months – 10 months old as the local civil registry office is slow to process. Why is this even necessary when my daughter has a MN1 and British Citizenship?