Adobe Flat Field
That was an interesting article. Eric is a cool guy - he is the guru of a lot of technical stuff in Lightroom. I used to order custom paper profiles from him some years ago when I was using some odd papers.
There is a similar feature/process in Capture One Pro called LCC = Lens Cast Correction. Some of the medium format technical camera folks use that because they are using large format lenses and tilts/shifts that result in vignetting and non-uniform color casts. What they often do is shoot through a translucent white plastic which is either held over the lens or placed in the filter holder. That way they can do a separate lens cast correction profile for each frame if "necessary" and they don't need to go hunting for white walls.
Thanks for sharing this. I am impressed that LR now includes this capability, though I don't use LR at all. Flat Fielding, like Dark Frame Subtraction, is a staple in the astrophotography world to eliminate the vignetting/distortion from long optical trains. Astro image processing tools like PixInsight have powerful support for these techniques. As John mentioned, also used in medium and large format photography.
I've used a white document on my computer screen to generate Flat Fields in the past, as uniform lighting is essential. People routinely use white tee shirts draped over the lens/telescope and pointed at the sun to generate Flats, as they are called. Long exposure noise reduction is a form of dark frame subtraction in-camera. I believe Capture NX has dark frame subtraction features built in too.