I have bought some construction wood from Amish in Upstate NY - and they have some decent (modern) milling equipment. Perhaps the electrical appliances thing doesn’t apply to making a living?
I think you’ll find that the Amish with modern milling equipment (or refrigerators for cheese they sell) also have gasoline or diesel generators. There are two principles at the heart of the Amish limitations on contact with modernity: avoiding “fancy” which they regard as violating the Holy Apostle Paul’s injunction against being conformed to this world, and an absolute prohibition on the use of credit. Purely utilitarian modern devices are generally allowed, provided they can be used without using any good or service not paid for in advance or at the time of purchase — utilities billed after use are forbidden not on the basis of being “fancy”, but on the basis that they are bought on credit.
Formerly from “upstate NY” too - southern tier, Chautauqua county, and knew the amish very well. We often used an Amish contractor on our building projects.
They can use power tools when they work for us “English”, but when they build their own houses, they must use traditional non-power tools, or they get in big trouble with their elders.
Rumspringa, as I understand it, is accepting the natural curiosity that teens have for worldly experiences, and their desire for their youth to make a conscious choice to accept the Amish life.