Manalto

I have a project in the works using unbleached Osnaburg and a compatible fabric. One of the nice qualities of these fabrics is the way they drape. Aside from not quilting too closely, do you have any other suggestions for how to preserve the suppleness of the finished quilt? The current plan is to use Warm & Natural batting, but there's plenty of time to change that. Would a layer of flannel be better?

The design of the quilt (Rail Fence) allows for stitch-in-the-ditch or another type of straight-line quilting, if that's preferable. Would using a longer stitch produce a more relaxed result? All thoughts welcome!