The info already posted for you highlights that any dual British/Irish citizens thinking of using this route need to be aware that The European Court of Justice has already handed down it's ruling on this and has dismissed an appeal based on the case of McCarthy v Secretary of State for the Home Department -Case C-434/09
This means that dual nationals living in a country of their nationality who have never exercised free movement rights cannot rely on European rules.
Currently, the Home Office are still granting EEA family permits and residence cards to family members of persons in this situation.
However, as previously mentioned the status granted is not legally held, it is solely policy decision by the Home Office and this could change anytime.
With all the changes to Immigration Rules just now it's a totally unpredictable situation.
But, it really must still be worth the effort to apply, especially as there is no financial cost.
Many have already successfully applied under this route without any problem.
