Does this set up work?
Ywing with R4 Argomech and Blaster Turret
-take focus as an action
-use focus to trigger Blaster Turret
-Gain target lock on enemy
-spend target lock to modify the Blaster Turret's dice roll.
I think it would work because you're spending the focus to preform the attack, so you would get your target lock on the enemy ship before you roll any dice, allowing you to modify your attack.