Comment by bilekas

> And then again at DUB outbound (US pre-clearance, so the normal Global Entry kiosk).

Pre clearance from the US means nothing for Ireland, it's also not Schengen.

> The only thing that surprise me was there was no passport check or any other custom/immigration at Dublin on the inbound leg.

Because you've done it on your outbound. Ireland is also a bit more relaxed, but at the same time they can randomely ask you for your papers.

> from the arrival gate to the departure gate

If you don't pass the control, if I'm not wrong you'll never need to be rechecked. The only place it has happened to me within EU was between Ireland -> Germany -> Greece. Probably because Ireland isn't Schengen