Many of the details in our sport can only begin to be performed correctly after hours of practice. That is how good habits become established. For example, it is the dog's habit to sit automatically. He is not doing so because he expects a reward or a correction. He has done it so many times, that he is in the habit of performing an automatic sit.
Repetition is certainly necessary to create a good habit.
That's why most great dogs have heeled a hundred miles more than an average dog and done hundreds of finishes more than most of their competitors. Although repetition in a familiar environment can help create good habits, keep in mind that it does not help him understand how to perform in unfamiliar circumstances. It is not possible to evaluate the dog's performance described at the beginning of the article without more information about how he performs in practice. However, you can evaluate your own dog's performance and determine why it changes in the ring.