1) Roulette mode - The player can choose to activate this mode before entering any clockwork level. It will randomise the equipment of anything selected, for example - it can randomise The two armour slots, The Shield, and The 4 weapon slots (assuming that they are unlocked). This can be beneficial in a number of ways, not only will it act as a crown sink, as you have to pay for each new stratum, and for each item type you want to randomise. The level of the item will be set by the stratum, E.g. Stratum 1 will have 1*, level 0, stratum 6 will have 5* level 10, this would almost be a "challenge" mode for those who have solo'd the entire game, and are getting bored, and give them a chance to experience new weapon combinations. The heat gained on these items will be turned back into crowns by the Roulette company at the end of the round, HOWEVER, because these weapons are not bound to you, heat loss is extremely easy, if you faint during a mission, the player who revives you gets 100% of your heat. Players who are on T1 or T2 cannot progress further than those tiers, as the weapons are not bound to them, thus they cannot use this mode to unlock further in the game
2) Treasure vault token. One at the end of each treasure vault - Giving you access to rare materials, or new/hard to find recipes/equipment. of course they will be high in price - similar to that as the King Krogmo Tokens. This will at-least make treasure vaults slightly more worth while without breaking the fact that its an easy level.
Considering reaching a treasure vault is entirely random I would not like the idea of exclusive items being available only by collecting tokens from there. Putting in rare mats that can be potentially be accessed elsewhere sounds nice, though rather than messing around with a token system I think it would be fine just to put the mats themselves in the level.
Or they could just boost the crown gains. Whatever.
Roulette mode actually sounds rather fun to play.