Can you insulate both the roof in the side attic if you baffle it and the kneewall going the entire length or no? I have been told multiple answers. There is a soffit that is vented the whole length and a ridge vent at the top of the roof. In NY.
I don't quite follow exactly what your situation is, but you are welcome to insulate wherever you want to, as long as it is ventilated on the outside (spray foam against a roof is an exception). More importantly, air seal on the conditioned side (heated side) before you insulate. Stopping air is A#1, then insulate.