I know there was a similar question a couple years ago, but I have a bit of a different one. When I took out the foam form, I saw voids in the refractory mortar in my barille grande. Someone asked if they should be filled in. The answer was if they are deeper than .5" it can be filled in.
My question is, if I do not fill them in and they are deeper than .5" (more like 3/4 to 1") will that be a problem? I put 4 layers of ceramic blanket on mine.