When you mention that you see the coordinates with 4 decimal places, what environment/situation is this in?
I'm using EPSG 31255 in the map. After tracing the vertices that are created have only 4 decimal places. I know that such a precision is not measurable, but I want that all lines and vertices lie accurate on top of each other. The coordinates of xy in this coordinate system have 6 decimal places, so i want this kind of accuracy, with snapping and tracing.