From the perspective of rejecting technology it is a good idea to not use any device which is using electricity. That means, for Amish it is not allowed to use television. The problem is, that a certain type of technology doesn't violate the Amish way of life, but is at the same time the pure evil. I'm talking about a hydraulic printing press which is used by many amish people. On the first impression everything is fine with the machine. It doesn't need any kind of electricity, and even a battery is not needed to drive the apparatus. But is the machine compatible to the belief in god? I'm in doubt, because a hydraulic printing press can produce many hundreds printed documents per day, and what is written in the documents is against the bible.
The danger is high, that if the printing press is used to often, this can destroy a society, especially if the written words are not the holy book but something else, for example comics, prose and modern journals. The hydraulic powered printing press is the weak point in the amish village. It is important to restrict the access, because the distribution of knowledge is dangerous. The problem with the printed word is, that it can be read alone, and this will isolate the individual from society. He can make his own thoughts and questions if the other people in the village are right. Books are forming a so called gutenberg-galaxis, which is an anti-amish doctrine to manipulate the mind of the younger generation. Every amish people should know how a typewriter and a hydraulic printing press looks like so that he can avoid to use it. Both needs no electricity, but they are dangerous devices. in a direct comparison, an electric driven fridge is harmless, because this machine doesn't isolate the people from the community. A cooler can be used together with other people. But a mechanical printing press has the dedicated goal to destroy the community. As more books are available, as more the people get lonely.
Let me describe the worst case scenario what can happen if technology is used to much. Suppose, the hydraulic printing press is instrumentalized to printing all kinds of pamphlets and church-critical books. They were distributed between the Amish-villages and the people starting to read books in´ their leisure time. From a formal perspective, no rule was broken. Because a horse transport vehicle is allowed and a manual driven press too. But after a while the community will get lost something important. If the people have read alone the books, they will have no need to talk each other. All what they want to know did they read in the so called newspaper. They will get lost their ability to talk to each other in a conversation, and this is equal to lost the faith in each other.
Teaching Amish people in a school is no problem. The time in the school is helpful for forming the character of the youth. But what it is a no go is using self-printed books in the education. Even if the books containing the bible, it is a sign of decadence. That means, a school with books can't be called Amish anymore.