I have a valid US Passport but never obtained a Certificate of Naturalization. I got derivative citizenship through my father. I used my fathers Certificate of Naturalization and my Green Card as proof of citizenship. Now that I have a US Passport is there any reason I should apply for a Certificate of Naturalization. I understand that in general it is a good idea but it was a hard fight to prove my citizenship to the US State Dept. (US citizen father had joint custody with my green card holding mother. they originally refused, said he must have sole custody but I proved that was not true using Passport Bulletin 96-18 which states that joint custody is sufficient.) The USCIS has different rules and says that sole custody is required. Any reason to fight for the certificate of nat?
I understand that a US Passport is conclusive proof of US Citizenship but is there any real reason to apply for a Certificate of Naturalization? Is there anything that would require me to have a Certificate of Naturalization that I couldn't do with a US Passport? (other than losing my passport which I assume I would have to get my father certificate again)