I would like the ability to save my lockers to open later. But, I would recommend that lockers to be opened should be limited to how many phones you destroyed.

For example:

Game 1: Destroyed 1 phone but lost. I get to open one locker. I save it for later.
Game 2: Destroyed 2 phones and won. I get to open two lockers. I save them for later. I now have 3 lockers saved.
Game 3: Destroyed 3 phones and won. I get to open 3 lockers. I use all them up now because there is a chance to get an epic card. I open up a total of 6 lockers.

Sometimes, I noticed that some of the potential winnings are just awful. Other times, I can have good potential winnings but I get none of them and just get 2 tickets, 2 rats, 10 gold.

I like the idea of opening lockers even if you lose because sometimes both players go through 3 minutes even and yet someone pulls off the win in sudden death. This method of opening lockers based on phones destroyed still gives players a sense of progress. The only thing bad would be you don't get anything for no destroying phones, which seems about right. This method may even give some satisfaction to players who feel they are getting sandbagged. And it allows players to complete events that require lockers to open to get the event items.