I finally found a working method to simulate noise toning in Krita.
Problem : Krita doesn’t support perfect conversion of black/white
toning taking both opacity and grayscale value into account.
Its current halftone filter isn’t capable of it without using a texture,
which doesn’t translate necessarily into a perfect result.
But there’s an alternative which involves using the Dissolve layer.
Before :
After :
You’ll however have to find a way to convert the white into opacity for it
to work. ( because of how the Dissolve layer works )
Q : Why is this not 100% perfect ?
A : Because you lose a bit of your gray value after a certain
pre-required operation. Though the loss is very minimal and neglectable.