Isn't that what mathematicians have always done with "level lines"?
First create a mesh (Sources -> Plane for 2D, or Sources -> Box if you want to do it in 3D). Set reasonably high values for Resolution on this source. Then use a filter to apply your function, either Filters -> Alphabetical -> Calculator for easy stuff, or Filters -> Alphabetical -> Python Calculator if you want complicated stuff. The "coordsX" etc. are your spatial coordinates on the mesh. Pick whatever color map you want (diverging types are good for this), change the limits on coloring, use a log scale, whatever.
If you do this in 3D on a box, you can then use a slice to scrub through the result on an arbitrarily oriented plane. You could visualize translucent isosurfaces of constant "error" and raytrace them. Or you could take the gradient of your "error" and plot as a vector field. With a bit of leg work you can add a fourth coordinate (time) and make animations. And you can combine all of these. Sky is the limit.
> For all the history of computational mathematical visualization, graphing equations has been done in binary mode
These are very concrete, non-mystical claims. But do you really think "mysticism" is better here?
The millions of brightly-colored fractal posters adorning walls in the 80s are a very clear counter-example to your claim.
Your app is cool and the visualization is neat. The hyperbolic claims of originality really detract from that.
I think your critique would be more effective if you left out the part where you shame the author's lack of knowledge about level sets
I think it hides your valid (if overstated) criticism of the author's exaggeration behind a non-constructive insult, and your comment would be better without that tone
The point about level sets is entirely that the author not only does not have the background to make claims about novelty, they have all the clues they need to figure out that they don't have the background.