How to farm B&B Event efficiently
1 - Use the Ruins Wheel to any point that brings you back to Luknaria capital (Do NOT use the Event Wheel)
2 - Enter B2F
3 - Auto-chest
4 - Enter B3F
5 - Auto-chest
6 - Go back to B2F and harken out
7 - Repeat step 1, profit
Optional - Get to A4 beginning and/or Copper Tier on MC (or whatever progress level needed to start seeing Seven Luminaries junk)
**Why though??**
Cause B&B follows classic Temporary Event rules, meaning that you can reset all Gold Floor Chests simply by using the regular Ruins Wheel... this has the distinct advantage of not reseting any of the actual progress in the event dungeon itself. In other words you retain access to the Harken in B2F and have no story encounters in the dungeon, but you get all the Gold Chests back.
Enjoy!