I'd prefer a removal of steely completely from Leprechauns as this is also one part of the game design that just does not sit right. Otherwise, a further nerf to say; 1 in 300k rate of steely seems fine.
Seeing that once a Steely drop is generated in server, it stays in the server for most parts since it is not a consumable such as scrolls, pots until a player NPCs or Quit the game along with the stars. Even with the recent nerf to it's steely drop rate, it still feels like the amount of steely generated is still quite significant and unsightly. Since this map's pure meso value per hour is already relatively high, low damage required (<3,000), non-moving mobs brings other steely maps to a further standstill of emptiness.