Statikk Shiv / Rapid Firecannon bug with double strike

When master yi hits his 4th auto attack, it's a double hit, but the charges on statikk shiv and firecannon only give him charges compensating the initial auto attack and not the second. Is Lucian like this as well? If so are these items designed to purposely ignore the extra auto attack mechanics from Yi and Lucian or has it been simply overlooked? Also how does sated interact with the item? Do extra hits compensate additional charge stacks?