Did you read the link Tony m posted on page 1 this is how  The ukvi will treat SS route, it seems if they believe you are using it because you would otherwise not qulify then it will be denied, i'm sure it is not compatible with freedom of movement to which the UK must abide, though you may well have to appeal..

For what it's worth anyone born uptil 2005 in the Island of Ireland  is considered irish so would be entitled to an irish passport, gets tricky after 2005  when it depends on your parents status

Exercising treaty rights as a irish citizen in the UK has nothing to do with the SS route.
 

UKVI are perfectly entitled to refuse any application where they believe it is an attempt to by pass the immigration rules. SS is a valid route to allow a non-EU spouse to reside in the UK.

Abuse or where it is thought to be an abuse of the system will result in rejection. There is a right to appeal in these circumstances.

Sadly there have been organised packages that have been created specifically to abuse the rules!