I am more than aware of what is needed for HC tags and also how getting a service dog works. They are not remotely the same method or steps, and nor should they be. Getting a service animal is a multi step thing. The licensing should be with the dog, not the human. the dogs are in need of training and then the humans train additionally with them for 2-4 weeks. The dogs can also be deemed unfit for use during schools. They try to match as best as possible but sometimes dogs just are not a good fit for their handlers. I'd want those dogs to be checked, not as much as the handler only. They really are working as a team, but since it is the last step, the card should only be given then or you will get con artists. Without that, any con artist could get a doc to sign off and then use a pet that isn't legit. If you've ever gotten a HC tag, you'd know it's not that hard to get.
Remember also service dogs are not just guide dogs too. They all have different jobs.
I think those of us with first hand knowledge realize how incredibly difficult this would be to do. Not that it couldn't be done or that we're against it. We just know it's not at all the same as a HC tag. So don't think I'm against it, you are just way over simplifying a process. Like how often should dogs be certified for? Who would do this? How can you make sure all those could have it done without stress of travel?
This is just complicated and not what you are implying. And again please don't think a vest would be enough to show. Not all animals can wear the same type. A card with a picture of the proven trained dog would be better or that vest could be put on anything.