I'm now at a point in the game where I own a few destroyers and try to keep the xenon in their sectors by my own. The AI is slowly getting back their forces and invade hostile xenon space (mostly because of my help, otherwise the xenon K always shred them).
Long story short, I like the new system for turret management and that you can assign different targets. My tactic is normally to disable all the L turrets from a distance with my main and L plasma weapons/turrets and have my M turrets on fighter defence (they can disable you very quickly if you don't pay attention to them). Once the L turrets are disable I like to go in close and give the K a broadside to destroy it quickly and enjoy the spectacular view of the new weapon effects
. For this I have to go to the ship menu and change all the turrets to "attack my current enemy". Once the K is destroyed, I go back and change the L turrets to "attack capital ships" and M turrets to "attack fighters".
My suggestion would be to reuse the useless main/secondary weapon grouping for L/XL ships and make it possible for the player to save "profiles" for their turrets. E.g. slot 1: standard config (fighters/capitals), slot 2: all on missile defence, slot 3: broadside (all on "attack my current enemy") , .... I think this could be solved with a turret profile dropdown (1,2,3,4 and linked to the wepaon groups) menu next to the turret behaviour field.