I don'd know how rapid it is, but I sure that there is a fairly measurable amount in 11,000 years (around 9,000 years BC). That being so, if Ireland measures the same at the present time, it would have been larger than Atlantis when Atlantis was around.
As for coastal deposition, no I did not. Not knowing Ireland I can't say if there is any saltmarshes; sand dunes; sand bars; barrier islands made of sand; etc., most of the pictures I have seen of the coast of Ireland shows rocks, cliffs, etc.