Been tinkering and come up with the following. I realized I could extend one corner out a foot without compromising access and this will allow me a wider O72 radius on that end. The tunnels, dog leg and different sized loops break up the bullseye effect. The light blue track would be the main surface. The purple loop would be elevated on a plateau with a curved trestles section at one end and probably a tunnel/mountain in the upper corner. The red track is a below grade storage yard which would be ~12-16 inches under the table. I would have a removable hatch to access the tunnels in the upper right corner and all the operating accessories would be within reach.
