I was very disappointed to find out that the eagle canteen pouches (with the elastic) have a very difficult time accepting a canteen cup. It seems that while the entire pouch is a tight fit the main hang up is in the elastic.
I was hoping to see if anyone here had removed the elastic on their pouch, and if so were you able to more readily insert and retrieve the canteen cup.
I’ve just learned to live with it. Since the pouches also serve as a general purpose pouch, I’d leave the elastic in. They will hold a stripped down MRE but you’ll need to cinch the elastic down to retain some of the smaller items.