Yeah, I put them on the top, but most rack systems are built with no lids. Then you put them on the side. Just measure the humidity and add holes as you go. I found it easier to put a bunch in the lid. Placement really isn't that important.

I totally stink at punet squares, but I think your right. As long as you switch the cinnamon out with pastel. And it would work the same with the AX x SpAX.