I once had a bisque kiln half full of pots that were too damp. They were also stacked on top of the dry pots. It was an interesting experience opening the kiln at ~150degC and seeing them jump around the kiln having some sort of gun battle, or maybe a popcorn party They never actually took out any of the dry pots but they were all thick so could withstand the bouncing crowd above.
If you are sure it is not your work then I think drmyrtle has a good idea with stacking all your work together. Make a bisque protection box and keep firing it with you work inside
I hadn't even thought about trying to get the same values but with different raw materials to see what happens. Good idea.
I am still waiting for my beautiful stoneware range. Right now it is blue, blue and probably blue. Haven't found anything with copper carbonate that I like, I have an OK iron rich glaze and then my colourants run out... Started playing with rutile which has brought me a lovely new blue