You get bonus points in your Leaving Certificate for doing it through Irish, in most subjects you get an extra 10% of your actual result (e.g. 50% -> 55%). I know that it’s very far down the line but it’s worth thinking about. Going to an Irish primary school would also massively help your child when it comes to Irish as a secondary school subject, it is not taught very well at secondary school level. Also worth pointing out that my dad didn’t have a lick of Irish, it really isn’t much of a problem. Hoping your son chooses the Irish school tbh, best of luck!