Nicely done on the suiban! What is the size? Slumping can be a concern on larger pieces once you add feet. Something that I tried on larger pieces was to add a support in the center the same thickness as the feet. It helped keep things from slumping in drying and the final firing. I know it isn't the most elegant solution, but most of the pots I made larger than 12" or so had a support built in to the center. Later I discovered I could make a support and put it under the pot for drying, so it did its job supporting damp clay. When dry, I fired the support with the pot in bisque (just set it inside the pot). Once it was ready for the glaze/final firing, attached to support temporarily with wax, which held the foot in place, but burnt out in firing. It still supported the bottom of the pot during firing, and using the wax made sure that whoever was loading the kiln didn't miss putting the support underneath the pot. If you are loading the kiln yourself, waxing wouldn't be needed, but it sure helped when relying on group firing with studio techs loading the kilns. It worked very well and the support was released leaving a nice bottom with just feet. The attached center supports look fine, because you can't see it unless you flip the pot over, but the perfectionist in me always knows it is there and is bothered a little by it.