That's excellent news! I know one of the links I posted for you mentioned that vets often cannot see and analyse damage clearly in the way a specialist can so that is great news. perhaps what he has is more related to some of the problems this breed can have because they are brachycephalic. Gagging and coughing are some common signs. Leo gags and coughs frequently when he drinks water for example. Lily goes into the cavalier snort quite a bit. The latter two also snore. Jaspar by contrast does none of these things-- maybe has doen the snort 3-4 times in three years.
I'm so glad it doesn't look to be a serious problem with his trachea and that his heart sounds OK too.
It's one of the things to remember about vets -- they are the equivalent of GPs and it can be good to get a second opinion on smething like an x-ray. Depending on the angle and the familiarity a vet has with a condition, s/he may or may not see things and those things may or may not be correct. It isn't a shortcoming but rather just the fact that they don't all have the same level of ability in particular areas.