I played this a few years ago.
Despite being born in the UK to a British father my character wasn't previously British due to parents being unmarried and being born after 1983 but before the 2006 rules update.
I'm not totally sure when but I think some time in the 2010s the 2006 update became retroactive so my character was allowed to play. Didn't have to do too many side quests - the main one was retrieving father's birth certificate.
My character also had to attend the endgame ceremony and swear allegiance to the queen, which seemed odd for someone born in the country and lived here all his life
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