The resolutions usually sit between 16x16 up to 64x64 on average for characters and objects, 128x128 for world texture atlases. The pixels cause a bleed/aliasing around it which is undesired for pixel art.
I have all the snapping features and pixel alignment enabled by default. In the test I set the shape size to match exact resolution as integers, removing any ( floating/double ) values, e.g 18x18 instead of 18,2x18,2, which should eliminate any possibility of pixel/color/transparency bleeding.
I'm including a basic afdesign test file, including the output, then comparing it to the png export from a recreation of the image in Krita. I understand both applications are fundementally different since one is vector and the latter raster based. Not sure if it's easy to filter the results to crunch the pixel on output or lower the vector resolution on the shapes itself.
The example files attached is quite small in resolution so some preview applications may display it with blurry edges. Best viewed in a raster application.
Krita Pixel brush output - nearest neighbour
Designer output - nearest neighbour
Designer output shown in Krita.
OpenGameArt.org has many examples for pixel art.
basictest.afdesign