i make lots of quilts using flannel- it only pils if it is an inexpensive- lesser flannel- good quality double sided flannel will hold up for years without pilling-
when i make quilts i want to be lightweight- cotton top, flannel back i either use an additional layer of flannel for a batting- or i use a layer of muslin- i just like them better with something in that center- adds body to the quilt- they are limp & sad with only 2 layers- (just my experience & preference) maybe put together a small practice square- with just cotton & flannel layers- quilt it & see what you think? then try it again with a center layer of muslin or flannel & see what you think of that- then decide
