We are looking at training an actual service dog for my 12 y.o. profoundly gifted AS son to help with sensory processing issues, i.e. helping with navigation, alerting him to traffic, people calling his name, familiar individuals in unfamiliar contexts, etc. A guide dog or a guide/hearing dog would have a lot of the skills he would need, but I understand that most guide programs are reluctant to work with children and reluctant to work with autism spectrum visual and mobility issues, so we will probably end up going the OT route. (okay, technically the OPT - owner's parents trained)
He is homeschooled, so classroom access won't be an issue until college, and obviously, the teacher would never be responsible for handling the dog, and college students should be able to cope with having a dog in class

without being distracted and unable to control themselves, one would hope.
What really upsets me about these tether situations is that they have the potential to make it harder for my son to use an actual task-trained dog to actually mitigate his disability.
He has demonstrated the maturity and conscientiousness to be responsible for a dog, and he understands the need to consider the dog's needs first, and the limitations on what a dog can do. He is involved in the daily care and ongoing training of my husband's service dog, so he knows what he is getting into.
It is a WAAAY different situation than tying a dog to a child and hoping the dog can babysit, but when I mentioned at a recent homeschool get-together that we might be training a service dog for him, a number of the other parents in our homeschool group looked puzzled, and finally one of them said something like, "We knew he was on the spectrum , but we never dreamed that you had problems with him running off. He seems so mature and well-behaved when he is out." Their conception of what a dog could do for an autistic person was limited to tethering. It took half an hour to explain what tasks were really possible and how useful they would be.