If a pinhole's diameter is more or less than optimum by 10%, the reduced sharpness should be noticeable. Also, in macro pinhole photography, a correction may be advisable for very close subject distances. However, such nitpicking may take the joy out of pinhole photography.
Two I did on Pinhole Day, the mural was the one I submitted. Details:
Mural - 5x7 Foma 200, 10 sec exposure;
Library building - 5x12 Kodak dental panorama x-ray film in curved film plane camera, 30 sec exposure.
Both films developed in FX-15, printed on Foma Variant iii FB paper in D-72. Small size scans of prints.