I have come across some omissions in my own search. I was looking for a branch of my own family in a townsland Kilkeny, which is in the 1911 census, and it is not in the 1901 census. It and they were there long before 1901. lol.
But in fairness, I think that there are some additions to be included later on.
Hope so, as it is a thumbs up for the information that is there.