...assuming 2♠ over 2♦ doesn't show extras (which seems to be the trend). Even if you play the (silly) agreement that 2S would show extras, then north must bid 2S with 4 spades over 2H. If you are still trying to cater to a 4-4 spades fit after 1H 2D 2H 2N your methods are seriously flawed, and you lose out on the very important hand type of 3 good spades, 6 hearts, the equivalent of 1S 2D 2S 2N 3H.