Just bought RC Astro's BlurXTerminator plugin for PixInsight.
This is a comparatively cheapo SkyWatcher 80ED with lousy "flattener" maladjusted, near the far-left middle edge of the frame, before and after running BlurXTerminator.
I had to check twice I was still comparing the same section of the frame, it's that radical an improvement.
It sure lives up to the hype and then some 😀