They need to just errata the card to not cost an action, and even then it would still be a costly option at 4 points with the defense penalty.
But superb on anything that can arc-dance.
It would still be marginal at best. If you're spending an action br/boost, that means your interceptor doesn't have a second action via PTL to either more successfully arc dodge, or focus. So while expose would boost its fire power (from 1.5 hits to 2.0)... Predator would also increase damage (to 1.94) without hampering defense if someone does manage to get a shot in... and it costs 1 point less... And Outmaneuver increases damage by ~.375... which is almost worth the same as .5 hits... So while Expose would be the best option offensively for arc dodgers if it didnt' cost an action, the point price wouldn't allow it to be competitive...
On A wings that could be a different story, but they're not as good at arc dodging.