Plain and simple - I'd like to see a RevokeReward action to complement the GrantRewardAction. This might make sense in the context of a mission or a group of missions, but mainly it would allow easier testing.

Once a Reward has been granted, there's no way to un-grant it for testing without having first made a copy of your piot record, and then manually replacing it.

You might also want to grant a reward in one mission and later revoke it, if the player does something to affect the status.
For example, you grant a reward for particularly smooth flying but, if the player does something bizarre, it gets revoked and they have to earn it again.