How do I resolve this unwanted blur effect while applying high contrast effects?

​@Libracentricart , have you been able to sort out your Layer stack to achieve the intended effect? 

The basic misunderstanding might be the assumption that the Adjustment Threshold and the Filters Grain and Torn Edges would affect a Layer’s the transparency. 

They do not and are not intended to. (With the Filter Gallery Filters that may be a difficult statement – those are very old and could do with some improvements anyway.) 

In your montage it seems you intend the person to be completely underlaid with white.

The samples you posted seem fairly different in principle – in the one only the teeth and text are white (with a sharp edge) and in the other only the eye, the person and the text while the photographs/illustrated elements extend further. 

As I showed in another post it is possible to apply such effects (or at least similar ones) to the black parts and the white ones separately. 

The setup is likely more convoluted than your current one but by working with two linked Smart Object instances for each individual photograph/element it should be manageable. 

Maybe I misunderstand – are you saying that you want a soft mask but you do not want the mask to be soft? 

You could use the Blend Mode »Diffuse«. 

Or mask the black and white elements separately. 

Which would also allow to use different patterns for the black and white elements. 

Always view hard-edged material at 100% View for an accurate preview.

100% in Photoshop has nothing to do with size. It means one image pixel is represented by exactly one physical screen pixel. At any other zoom ratio, the on-screen image is resamled and thereby softened.

Please elaborate on what the problem is. (edit: … or what the intended result should be)

Could you please post screenshots with the pertinent Panels (Toolbar, Layers, Options Bar, …) visible?