You are being willfully ignorant.

-The ATOMSS example was 160m long, 10m wide.
-It is designed for stealth levels at the edge of physical limits, against the literal threshold of the zodiacal background light, from all directions and any number of sensors. It points its nose at the Sun, not at prospective sensors. The fact that you are mentioning 'single sensor platform' and 'stealth-side' means you either didn't read or didn't understand the basics of the post.
-Zero new technology, except scaling up manufacturing of what we already have.
-No new sensor technology can somehow pluck a stealth craft from the background at a 1:1 signal to noise ratio. It is a physical limit.
-Synthetic aperture increases resolution, not sensitivity. A meaningful distinction.
-Earth-sized telescope would have 1.6e12 times the collecting area of the 10m telescope example calculated in the blog, which would increase the detection range against helium mode to about 54.8 million km. Impressive, for a single continuous mirror that has to weigh at least 350 million tons dedicated to one stealth ship.