First try - zero loot. Second try about 1/9 rooms had loot. I prefer scarce loot, so I’m happy with the odds. My own game is 1/6 chest room odds with 1/6 mimic or 1/6 empty depending on character.
One more question: The Items list goes up to 8. I assume that means a d8 is used. Or when you get 2 rolls in a 3x3 room that means add 2d6 rolls together?