This is because the plugin combines Raycast and Player Reveals functions. Achieving pixel-perfect precision might lead to a conflict between these two features.
Currently, you have to set a standard radius to avoid blurring, as there's no square radius option yet, if I recall correctly. Let me find a way to implement pixel-perfect square scanning.
I'm not sure they will work together perfectly. Using pixel-perfect mode might require temporarily disabling those two functions, for example.