backyard= no distractions
front yard = distractions
Yes, focus (engagement) is key to all training. If he/she is not engaged, training just won't work well.
Get it to the point of awesome in the backyard.
Then get a person to sit in a chair in the backyard and again get it to awsome.
Then get someone to sit in the chair and another person to walk back and forth in the yard and again get it to awesome.
Then get a person with a dog in the backyard, and a person walking and a person in a chair with a radio playing and again get it to awesome.
Then try the front yard.
Have you looked into perch training?