To legs-akimbo: A condensation line is always present in any wall material taking up moisture. By adding more material on the inside of the outside wall the condensation line would be brought further in. Where it has more difficulties to evaporate away. The condensation line should be brought outwards, as far as possible, to keep the interior wall as dry as possible - as warm as possible.
At the point where water evaporates from a wall we will find the coldest spot on it. Evaporation causes a cooling down effect. Try to wear a wet jumper to keep you warm. So the idea of insulating a breathable wall is to bring the point of condensation as far as possible away from the inside, the habitated room. To make it comfortable. The nearer the condensation line is to the ouside the faster the water can evaporate.Before it builds up and causes a damp/cold spot. To combine several different materials in the construction of an outside wall the individual LAMBDA values have to be considered.
Agreed , most Irish architects wouldn't know what it means. But it is very important, check also for the "sick building syndrom" in the www. to see how it can go wrong if ignored.
And using the dot and dab method for drylining : spot on. It is faster, cheaper and gives a chance to eliminate any uneven wall surfaces, making it possible to turn a crooked wall into a straight wall. But you have to scrape off any wallpaper and paint and loose plaster from the old wall before.