I can see Eindhoven working. There are a lot of Dutch tourist who come to Ireland and it will also work for people in Belgium and North-Western Germany. There must be close to 40 million people within a 2 hour drive of Eindhoven. Plus, it will give business in the North-West direct access to one of Europe's most important commercial/industrial areas.
However, it could impact on the possibility of Dusseldorf returning or the suggested Cologne/Bonn route ever starting. It also reduces the possibility of an Amsterdam route to almost zero (I always thought AMS was the most plausible major hub connection from Knock).