I'm not sure what your cauldron arrangement is based on that wording -- I'm not familiar with what is popular or common when it comes to builds -- but I can say I also had a lot of trouble with my spice rack the other day.

My cauldron is positioned in the middle of the room, and the spice rack refused to accept numerous spots that I tried. In the end I built a 2-meter vertical pole and attached a 1-meter horizontal one to it, then put the spice rack on the horizontal piece. Looks a bit silly but it works.