"When you perform an attack that hits, before dealing damage, you may cancel 1 of your [crit] results to add 2 [hit] results."
...
Wellllllllll, I'm not going to lie, I hadn't really paid attention to the limitation of 1 crit before I started posting this; instead, I hastily made my way to the computer with delightful thought of Marksmanship+Mango Cannon+Merc Copilot shenanigans to possibly turn 3 hits into 6 damage, if they found their mark.
Reality continues to ruin my life.
That said, Bossk is the first crit dealer who doesn't care about shields on the target; you know, as long as the crit you have in mind is Direct Hit or a successful Minor Explosion each time. (Among the best crits to score anyways.)
Mangler Cannon might be auto-include on him, what do you think? Since you're limited to 1, and The Mango gives you 1, there's little else I can think of to capitalize on the ability in as simple of a way.
I'm pretty sure that you won't want to pair him with Calculation; the crits have to have made it through uncanceled by defense dice before you can activate his ability, after all. Marksmanship is a thought, however; with only 1 agility, defensive focus is the least likely thing you'll need.
Merc Copilot at Range 3 is too finicky (you know, unless that limitation of 1 wasn't there), but you're once again tempted by that Range 3 HLC shot with said Merc Copilot that could, say against a Y-or-B-Wing, nail 5 damage into the flying coffin's lid with relative ease...
Autoblaster doesn't find a home on him, because the opponent can cancel crits before canceling hits with that cannon. Ion and Flechette cannons aren't any more useful with Bossk than anyone else, either, since the dice result cancellation comes after determining the attack hits, which is also the timing for Bossk's ability, so there's no way to add more damage with those guys. (You either cancel all results for the cannon first and can't trigger Bossk because there's no crits left uncanceled with which to do so; or you cancel the crits with Bossk to add 2 hits, and then cancel all dice results.)
And then there's the half-priced Z-95 that comes with it, if you take the title. Not quite the equivalent of adding 2 hull and 2 shields, since you lose some attack in the process, but still probably something to keep an eye on. Almost certainly better than a Dead Man's Switch.
Plus, there's the Bossk crew card. What do you think, will he be like Dash pilot vs Dash crew, and essentially be the opposite ability?
"When you perform an attack that hits, before dealing damage, you may cancel 2 of your [hit] results to add 1 [crit] result"?
Much less useful than the Bossk pilot, if it works that way. Here's hoping it's more like the Vader pilot vs Vader crew, and have some completely unrelated ability.