Greeting Mom after a grocery shopping trip.
Boundary training is one of the best things that you can ever teach your dog. No matter where the boundaries are, you can use them to help teach more. Once a dog "gets" the idea of not crossing an invisible boundary; their capacity to learn other boundaries goes us. This type of boundary training that I am talking about is about not going into certain rooms, going out doors and gates or whole areas.
Teaching a boundary like the door above will NEVER, EVER be a waste of time. Once your dog is solid on a door boundary it is very easy to move to other doors. Many dogs generalize well and will hesitate before going out any door. Some need a tiny reminder of an error marker; a simple ahhhh as they consider going through.
Door boundaries can take time to teach; especially if you have a guaranteed bolter. But by simple rewarding them for NOT going out the door the learning curve can be achieved quickly. When you start teaching a boundary you must leash your dog, in case.
Learning boundaries does not mean that your dog will never be able to go a particular area but that they must wait for a release word. Your release word can be anything; something that comes to mind, you can remember and is saved for that specific reason. You can use the same release for feeding, stay and many other things where a release is needed.
Just yesterday, I needed to use a boundary as we have come to a new house for a couple of weeks. Elsa quickly realized that running out is not an option and she must wait until told that she can. I only needed one ahhh for her to understand that this too was a boundary.
You will NEVER, EVER regret boundary training.