So I've been farming for the skeleton key for about a week into playing Second Run and it hasn't dropped on either map 3 or 4. I decided to jump onto different maps and let the game run while I'm at work (12 hours or so at a time) and while I sleep. I've never received a single map item where it says "enemies can drop this". Not one single item with the exception of different items. Either the drop rate is so incredibly low, or there's a bug not allowing enemies to drop the map-specific item.
So I've been farming for the skeleton key for about a week into playing Second Run and it hasn't dropped on either map 3 or 4. I decided to jump onto different maps and let the game run while I'm at work (12 hours or so at a time) and while I sleep. I've never received a single map item where it says "enemies can drop this". Not one single item with the exception of different items. Either the drop rate is so incredibly low, or there's a bug not allowing enemies to drop the map-specific item.