So I am definitely building this and bought his plans just as inspiration. Mine will be perm. A few general questions. Why are his openings circular versus rectangular? I could see putting some drawers in there if rectangular. Only reason I can come up with is arches are stronger ala Roman Arches in medieval times. I understand the reasoning also behind having two pieces vs one and its weight due to it having to be mobile, but in a permanent situation it could have solid partitions in the middle or am I missing something? TIA