The cue is not so bad near max for passed hand - its more the 4♠ bid- better to bid 3♠ as absolutely forcing to game. Then GIB East can bid hearts, West can rebid spades. East should only continue with at least 13 8421 points. This measure 8421points (8 for ace, 3 for king, 2 for queen, 1 for jack) that's already part of GIB bid evaluation is so underutilised.