All, here's the final design for my version of the 11 x 11 layout for those that have been following this thread,
I've shown the perimeter incorporating the turntable and also the proposed lift-out section. The table top consists of 1/2" plywood topped with 1/2" Homasote and would incorporate the area of the lift out. There would be no modifications to the underlining frame. The lift-out would be then be cut out of top insuring a perfect fit and alignment. Its shape is rectangular with the upper right corner clipped along the joint of the curves.
Note that there are no 90-degree inside corners. The triangle inserts serve to move the curves farther from the table edge.
Jan