#2. Have The Miz bide his time and cash in later

The Miz told fans after Hell in a Cell that he would wait for the right time to cash in his Money in the Bank contract and while that's a little anticlimactic, it might be better to play the long game. Furthermore, it might be better if The Miz just doesn't tease a cash in for a while.
The point of the Money in the Bank briefcase is the element of surprise. With a whole calendar year for a Superstar to cash in his or her contract, that moment could come at any time. Making it unpredictable and not telegraphing Miz's intentions immediately buys time for WWE and also builds fans' anticipation.
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In the end, WWE might just be better off keeping The Miz and the briefcase in their back pocket for now. At least that way, the company can save the briefcase for when they really need it and The Miz can continue to build up heel heat in the meantime.