I have used 2 layers of low loft poly batting when I wanted a puffier look and didn't have anything else on hand. Suggest you make a sandwich sample, say 18"-24" square and see if your machine will handle it and if you like the resulting look and weight. I think it would work depending upon the density of your batting. Also if you use different types of batting they may shrink at different rates so you might consider presoaking it. Lastly if they have different quilting space guidelines use the smallest spacing rule of the two to be safe.