I've been thinking about this and about the only thing that I can come up with (other than having options) is to have IG-88B's Gunneresque effect give two bad choices.
If you had IG-88B with an HLC, Ion Cannon (or Flechette Cannon), and FCS you could take your initial shot with the Ion Cannon. Your target takes the same result if they leave 3 uncancelled as if they leave one. If they decide not to spend tokens to block everything they'll take one damage and get an Ion token. If they chose to spend the token to block all of the damage then they are looking at taking a target locked HLC shot without as many tokens as they had.
Not sure if that's worth spending the points on or not.
It's a little off the topic for this thread but I just realized that one of the benefits of the Mangler Cannon that I've overlooked is the way that it will work with Gunner. Somebody like Soontir is really going to have to think twice about letting that point of damage slip through so as to not trigger Gunner.