Hello! I am new to the forums, and have been using Krita for a few weeks and really enjoying it! My primary use for it right now is for working on pixel art sprites for a video game project I am working on which is why this feature suggestion has come to my mind.
What I want to talk about can be very easily explained by looking at how the brush and line tools work when using the u)_Pixel_Art brush. I have attempted to attach an image as an example.
With the pixel art brush selected, the cursor snaps to pixels on the canvas which is extremely useful because it clearly shows where the pixels will appear when you are drawing onto your image. However, because the cursor snaps to the pixels, there is no way to see the actual position of your mouse cursor, which means it is difficult to draw precisely with the brush tool.
This is only an issue if you are trying to be very precise while drawing long lines, or any kind of curve with the pixel art brush. What happens is, as you move the cursor, while you can intuitively tell which general direction the brush is moving in, because you cannot see how close you are to jumping to the next pixel, you will probably paint at least a few pixels in the wrong place.
For example, if you are trying to draw a straight horizontal line from left to right, you would move your mouse from left to right. But inevitably, your mouse will not move in a perfectly straight line, and the cursor will drift either up or down slightly. Eventually, the pixel art brush will jump up or down a pixel, but there will have been no way to predict or correct for this. (This example is a little silly if only because you could use the line tool to draw a straight line, but hopefully it illustrates the point about mouse drifting, which happens regardless of what kind of line you are trying to create).
I think a simple solution to this problem, which would potentially make precise pixel art using the pixel art brush much easier, can be found when looking at how the line tool handles the cursor when using the pixel art brush. The line tool still shows the square guide snapping to the pixels in your image, but it also overlays a crosshair which shows you the real position of your mouse. This way you can tell if your cursor is near the edge of the pixel, which edge it is near, and correct for this information accordingly, allowing the user to be more precise.
My feature suggestion is that maybe the pixel art brush (with the brush tool selected) could have a toggle option for showing an actual crosshair which moves directly with your mouse over top of the pixel guide which snaps to the grid. That way the user has the information of where the pixel will land, and also where the mouse actually is, for precise work flow that requires less corrections.
Thanks for taking the time to read this suggestion 
-Seb
