Yes, that would be one way to make it noticeable. If all land/sea floor lifted, gradually, 1.2km into the air, we wouldn’t see it. I also Flubbed the per-km increase of the ruler and edited it to correct the increase down to 20cm per km. So as far as our ability to tell things are 0.02% further, no mere mortal would recognize it. But with a lap band around the Earth, we’d definitely notice the new halo floating above us instead of being a tripping hazard.

That reminds me of a fun fact about how the increase in circumference does not care what your starting values are. If you wanted to wrap a rope around a soccer ball, then make the rope lift 1m above the surface of the ball all around, you’d do probably do the pid math like (pid2)-(pi*d1) :

3.140.022m=0.069m of rope around the ball
3.14(0.022+1+1)=6.349m of rope to float 1m above the ball
6.349-0.069=6.28m of extra rope

Then do it for the planet.

3.1440,000,000m=125,600,000. 00m of rope around the planet
3.14(40,000,000+1+1)=125,600,006.28m of rope to float 1m above the ground 125,600,006.28-125, 600,000= 6.28m of extra rope.

1m above, or 2m greater diameter, can just be fed directly into pid as derived from pi(d2-d1) since we know it’s a basic request to lift it 1m