after the quilt is quilted and bound if you wash it the stiffness of fusable web softens up- unless you use one of the no=sew ones...which nancy uses often- because she makes wall=hanging art quilts that are not meant to be washed- so the stiffness doesn't matter.
i have (tried) to use fusable web to baste (once) it did not work so well for me- the fusable i (tried) to use disappeared in the batting- did not adhere to the fabric- it was a mess- but i was probably just using the wrong stuff- maybe try it on a small project-like a place mat or something and see how it goes-
but the fusables do wash away-soften up when the quilt is washed.