County Louth's par-3's were indeed excellent. The fifth was the best of them, I thought, but I'd put the Dell at Lahinch ahead of it.
There are lots of holes in this list that are overrated. The silliest choices are the 3rd at Woburn, the 9th at St. Annes, and the 16th at Cruden Bay (unless it has been totally changed since the last time I was there, and even so, there's no way it is the best par-3 16th hole in the UK).
I've been in Scotland the past week and just off the top of my head, would choose the 10th at North Berwick (West) and the 9th at The Renaissance Club over those listed. The best par-3 at Askernish was the 14th, but I can't choose that over Calamity.