I believe that the eircode dataset is one of the most highly requested sources, but it’s a private for profit database.

If you are aware of such a dataset that a public body is hosting, then it would certainly be something to include. Convincing (and helping) the public bodies to publish their data is still a big task.

I believe that An Post built a similar system many moons ago, and they should presumably be more amenable to open-sourcing.

The handling of the whole Eircode thing makes my blood boil, to be honest.