What is measured, and what is not
Measured: the panel's outer corners on 152 frames, and 1,309 luminance edges of its top and bottom. A rigid-body turntable solve fitted a single camera plus one rotating rectangle — 0.28 px RMS horizontal, 1.06 px vertical.
Derived, not photographed: the screen rectangle itself. Every render shows the display off, so the rectangle is computed from the 43-inch panel's real active area.