Permanent EUR undervaluation means that we Europeans are getting poorer on a permanent basis. Sometimes that can become quite obvious, for example when American employees working remotely and pensioners buy up the property market in Spanish holiday resorts. However, even disregarding such obvious effects EUR undervaluation means: we give away our export goods at cheap prices and pay over the odds for our imports. 

I am not sure whether this factor was sufficiently considered in the cost-benefit analysis of those who were responsible for QE and regulation.