Yes, GunCO affect both Ricochet & Blast (note blast proc [Xata]'s Whisper Void again)

Evolution II : Perk 1: Feigned Retreat: Increase Base Damage by +40 & +40% Damage to enemies below half Health
OR with recomended [Scourge] primer, Perk 2: Paragon Essence: Increase Base Damage by +40 & x0 Critical Chance on Bodyshots, +150% Critical Chance on Weakpoint Hits (HUGE DPS INCREASE)
Evolution III: Perk 2: Rapid Reinforcement: +50% Reload Speed
Evolution IV: Perk 1: Commodore's Fortune: Increase Base Critical Chance by +14%

Arcane:
can go for Secondary Deadhead (less damage) for easier play ex: if you're running glaive and didnt want to bother tiddious extra step to activate outburst: swap primary-hit melee-swap secondary-repeat-unload carnage-swap back to primary(repeat)
Secondary Fortifier if warframe need more sustain

or Swap polarity to make Magnetic & Heat to delete Thrax and Eximus