When producing "Sharpened Stick" out of "Wooden Stick" it always gives a full stack of 5 sharpened sticks. Regardless if I choose "sharpen a stick" or "sharpen all sticks" and the amount of piled sticks is of no matter, too.

Same with producing "Improvised Arrow" with feathers and sharpened sticks. I always get a full stack of 5 arrows.