Irish Passport inquiry through FBR

Hi guys,

I am born in Australia and have recently submitted my FBR through my Grandfather. I'm hoping to get my certificate back maybe May/June of next year based on the timeline. (I submitted end of July) My issue now is when it does come to applying for my passport, I will be over in Europe. It says that when I apply for my passport I need to send my Australian one over with my forms as well. Is there any way that I can use some other form of identification? I'm not really relying on the passport, but it would be really good to have it so that I don't have to stick to the 90 days of travel. Please help!