Fair enough. Yet the question remains: can you meaningfully lower arrests/convictions that resulted from stop-and-frisk, by changing the laws regarding the part

Fair enough. Yet the question remains: can you meaningfully lower arrests/convictions that resulted from stop-and-frisk, by changing the laws regarding the particular charges that are brought? If it's about a 'fishing expedition', then decriminalizing marijuana might dramatically drop drug charges, but not move net arrests much, as officers simply find something else.