They look like you need a dual-busbar style of board as they don't have flying N. Not sure if that is common in ROI? Certainly it seems to appear in EU for the double-pole protection.
But they actually need double-pole protection (i.e. thermal-magnetic on both L & N) presumably from legacy of not having N very much tied to E.
The Wylex and Crabtree compact RCBO are both neutral-switching and Type A RCD, so they meet the requirements for selectivity with an up-front delay RCD on N-E faults, and the added isolation makes testing a bit simpler as you can flip the breaker and insulation test the final circuit N as well.
I think the recent compact Fusebox RCBO are also neutral-switching and type A, would not be surprised if they all come from the same factory...
