He's been in Europe for two years and there's no evidence that he's even been to Ireland and if he has, it hasn't been much or for long. His Irish connection comes from an "Irish-born grandfather," which sounds like a guy who'd have left Ireland as a child in the 40s or 50s and grew up in the US; contact would have been difficult and the motivation to do so would have diminished with subsequent generations. He'll surely have grown up dreaming of the Red, White and Blue rather than the Boys in Green. We're Plan B. The real use for his Ireland eligibility is the British WP IMO: only the richest clubs in Belgium can pay Championship-level wages and that won't vary according to which MNT he plays for.