It has been over a week since I last attempted to dry the mycelium. I have been checking on the air dry process, and two days ago I realized that all of the pieces are around 50 percent of their original mass and not getting lighter, so they are probably fully dry. The instruction from the grow.bio are probably for a different mycelium mixture that they used to sell, so the the final mass could be different. To check, I ordered a moisture meter that I need for the full chair anyway. It arrived today, and each mycelium piece registers as 5 percent or less moisture, which is the low end of what grow.bio says. They say that a full dry piece should be between 5 and 12 percent moisture, so everything is dry.
I can now continue the design for the chair which I began last Wednesday, and then possibly order more mycelium. I checked the sizing of the kilns at school, so I know what size I can make the chair, and I have a space to work, so I just need to set everything up.