no sorry dont know of a tutorial for that specific effect.
but it’s a pretty basic effect, if you understand what the stencil does you’ll figure it out easily.
you just need to quantize the uvs to pixelate something,
then sample the scene color twice, once with the pixelated uvs and one normally.
and then sample the custom stencil and compare with the value for your object.
then use that result to lerp between the quantized scene and the regular one.
here’s a plugin of mine it’s open source.
it has several material functions to quantize and to deal with stencils.
and has an “equals” that could be a bit faster than the “if”
if you don’t want to use the lerp you can use the If, though it could be slow.