I am aware that there are a sizeable number of people in Great Britain (I believe about 6.7 million according to one estimate, or close to 10%) who are eligible for Irish passports since they have a generational relative who was born on the island of Ireland - under the Irish rules this includes both the Republic and Northern Ireland. I appear to be one of these myself since my dad was born in Northern Ireland. While he has only held a British passport to this point, anybody born on the island of Ireland is allowed to apply for an Irish passport, and the right is the same for their child, even if they were born outside of the island of Ireland. According to the Irish government's guidance I would not need to sign Ireland's Foreign Births Register as I have an Irish (which includes both the ROI/NI) born parent (the foreign birth register requirement seems to apply if only your grandparent was born on the island of Ireland), and would simply need to send a copy of my dad's full birth certificate with an Irish passport application to prove that I am entitled to Irish citizenship and able to receive an Irish passport.
As someone who is opposed to Brexit and wanted to retain the right to freedom of movement and EU human rights protections, I have been considering applying for an Irish passport since the time of the referendum result as I am eligible and having dual British/Irish citizenship would enable me to travel freely to the EU under the pre-Brexit terms provided I use my Irish passport, but so far simply haven't been able to get round to doing so, largely because of the pandemic delaying things. What I wanted to know would be if any people here who have a similar background to me (such as an Irish or Northern Irish born parent) have done so or considered doing so as well?