For n=36, I kept the published 36-circle triangular-lattice centres and exhaustively searched the 61^3 (±3e-8) nine-decimal integer neighborhood of the three triangle vertices. Exact integer checks covered orientation, every circle-edge clearance, and all pairwise centre distances. The feasible best frame is (0,0), (17.464101616,0), (8.732050808,14.844872395), reducing the third y-coordinate by one grid unit and the area to 132.066642035186220856. Joint centre/frame optimization is the natural next step.
P66 · Unit circles in a minimum-area triangle · Discussion