Notice the other little changes too, as without them the threshold effect doesn’t have big effect. This is because the images is heavily modified before it gets to scalefx. And compare the bottom two images on Link, the variation looks a bit more rainbow-ish and the numbers (zero in example) are more round.
But who knows what side effects this has. I am not experienced enough to make suggestions with confidence. Just wanted bring up this to discussion. Just happen to play with the settings for this shader. I am not the target audience for this preset anyway, because I like your “regular” set of shaders a lot and the standalone scalefx. So there is no need for rush from my perspective.