-If ammo isn't an issue, you can replace exilus with Ruinous Extension.

BUILD DETAILS
-We choose magnetic progenitor to maximize unique statuses to boost Galv Shot damage (reminder KNukor has its own unlisted status 'microwave' that enlarges enemy body parts & counts for Galv Shot), especially for SP Corrupted & primer versions of the weapon.

-Normally building for crit is worse than slotting other mods but here it's all we have left. Outside flat crit chance sources like the unranked Combat Discipline - Arcane Avanger combo on frames, Adarza Kavat or Harrow 4 will boost damage even more.

-More fire rate over crit mods would do no good, since it would waste your ammo for no real benefit on most Corpus units. For the tanky ones you can always add abilities/primary/melee.