None of that matters really as light rail only serves the population that lives close to it. This means you need population density along its line.
I don't use the Luas but it appears the Stephens Green line does a lot better as this goes through residential & office buildings the entire length & doesn't share the road with cars much. The other line does up the Naas road for a part of it with commercial parks on either side & very few passengers in that area.