Sorry to say I do not have much to add to the advice already given.

The one thing that Smokey needs above all else is a very calm, strong leader that he can rely on with 100% confidence. You provide that for him and that is as good as it gets.

The point made about genetics is an interesting and valid one. A genetically "shy" dog is one thing - a degree of improvement is possible. Smokey is living proof of that. A dog that has inherited nervousness as a trait is always going to be a nervous dog.

Keep on keeping on and I'm sure you will continue to see small improvements which, when you review his overall behaviour, are really pretty major achievements.