Opened doors mean nothing at all.
Teaching a dog to wait at threshold (doors, entrance, stair...) is very important. Not only can it save a dog's life in extreme cases, it can also benefit all dogs by teaching them how to stay tuned in to their owners, control their impulse, and stay calm even when they are in an excitable situation.
In this short clip, I just arrived at a beach and the dogs were obviously excited and looking forward to play. As you can see, after I have opened all the doors they stayed inside and none of them made an attempt to rush out.
Not only that, a man with his dog and his family then walked by our vehicle, the man stayed very close by with his dog to look at me and my dogs, because I never released my dogs to get out, they continued to hold their place inside despite the fact that all doors were fully opened.
This is not a difficult thing to teach your dog, it is nevertheless a very useful lesson that any dog can benefit from. This lesson can be carried over to help the dog in other areas as well.
Teach your dog not to rush through any doorway, stairs and any entrances or exits until you have released them to.
An opened door means nothing--what should mean everything to your dogs is your guidance and direction.