What kind of less than perfect piecing are we talking about?
I'd say if your seams are coming apart/stitch length is too long to use something like warm and natural. A poly or any fluffy batting will start coming through the seams.
If it is that the points or seams aren't perfect, yeah, get a fluffy poly batt so it puffs up around and hides the imperfections.
If portions of the block don't lie flat from workmanship, you can decide if you want to quilt it down and out with a lot of quilting, in which case, W&N type. Or, you can let it puff up with less quilting and a poly batt.
Not sure on the other less than perfections may come up, but there must be more.