The reason that the "correct" labeling has not become widespread is probably because, for the most part, it is not enforced. I don't personally know of anyone who was ever fined or prosecuted for incorrect labels. If a few people have been fined, it was most likely large, high profile dealers, or more likely, somebody whose labeling got noticed only because of some other infraction they were caught on, first. Once you get caught doing something wrong, they always look for other related things to make it more worth their while.
It is unlikely Fish and Wildlife will have manpower to start randomly checking FedEx or Delta packages. HOWEVER, if your package ever comes under scrutiny for any other reason, then incorrect labeling might get noticed and cause problems. Since it is pretty easy to comply, you might as well at least make the effort to do it as unobtrusively as possible (even though the chances are slim that anyone will ever notice a lack of labeling). If it looks like you "more or less" complied, you might be able to win your case before the judge, even if F & W wanted it done slightly differently, especially since the language is somewhat vague on what constitutes standard practice. But if it is not labeled at all, you probably would lose.
Of course, I am not a lawyer and am just going by logic, and what I have read about in past confrontations with US F & W. Anytime you deal with the government though, you can't always expect logical behavior.
