I thought the 3 minute separation was going to be the hardest
In fact the week before the test, we failed it during practice.....my dog howled and lunged the entire time. But on test day she did it perfectly! Different 'stranger' that day and a whole different attitude. I was really worried about it and worked on it a lot.
The only other thing that we found difficult was the recall. The recall itself was fine, my dog has a near perfect recall off leash. But for the test it is done on a 20 foot line, my dog hates working on a long line. It gets all tangled up in her feet, no matter how carefully I try, and then she stops and tries to untangle herself. We had to work the most on that! Miraculously, she didn't get tangled on test day!