I reject the premise.
First, I think it's highly unlikely an effect can be overpowered no matter the cost. It simply doesn't make sense. If Luke is OP at 30 points, but not worth playing at 45 points, there will be a point cost between 30 and 45 points at which Luke is cost-effective.
Second, even in the event it happens (e.g., 1.0 pre-nerf cloak), FFG has not precluded errata. All FFG has done is make balance more easily (and more quickly) adjustable without issuing errata.
