Not to add to the table yet, until the chip is working. The calculated value however explains much.

KnC Promised Figures

The area is package area, actual chip area will be significantly smaller, so the η value will be higher.
Edit: The die area is exact (55 mm x 55 mm), the package is 90 mm x 90 mm. Source: https://www.youtube.com/watch?v=by-je8XRCdY

Second edit: I must had misunderstood the video when I had been watching it for first time. There they stated quite clearly, the chip (the package) would be the size shown, about 60 mm x 60  mm,
not the die, which will be much smaller.
The conclusion:  η  should be significantly greater than 90.