Sprint all the way through the catch, rather than slowing down to catch. While catching at speed is a more difficult than when standing still, it is an important skill to learn in order to prevent defenders from running past and getting a block.
Add a defender to provide a realistic mark; this is shown as a faded block on the diagrams.
A should make it clear if the disc is not coming; a clearly visible fake (or audible) signals that the long throw is not coming and B should cut underneath; this also ensures that B is looking at the thrower.
Cuts/throws are not commonly seen in games
Too many people in lines, not enough reps per person, too much time wasted and standing around.
Encourages bad thrower habits. In games, you don’t stare down the break lane, make a series of fakes and then throw throw the loopy around break for no gain
For a more game-like drill that will push your limits, try Break to a Point instead