How about exotic ghosts and exotic sparrows? And how about faction specific ghosts and sparrows? And how about offering a booster drop like ether seeds for Taken? And how about considering an elite, extremely rare drop or boost that works like a Three Of Coins but allows the player a limited time to double equipped exotic gear and\or weaponery? Those would be extremely valuable in nightfalls for one example but woulld need a time reuse buffer like ammo synthesis and would never be permitted in crucible like ammo synthesis.