Missing slot is [Magnetic Might].
Secondary Enervate is final absolute crit chance (like Arcane Avenger). [Velox Prime] has terrible base crit and the highest fire rate of any single pistol, making Velox Prime one of the best users of Secondary Enervate.

"Why not use (other build)"

• Cascadia Flare + crit: Much worse 3s burst dps (~30-35% dps loss), much worse 30s sustained dps (~30% dps loss). A Cascadia Flare build will have an easier time killing the first enemy for Galvanized stacks, but this is not enough of a reason to use Cascadia Flare.
• Secondary Encumber + crit: MUCH worse dps. Calculations involving Secondary Encumber are difficult, but the critical chance on this gun should be enough evidence. There are not enough mod slots to make crit and Encumber work together. Please don't do this!
• Secondary Encumber, full status: Much higher potential in exchange for longer time-to-kill. Most of Encumber's damage comes from free status effects (heat, electric, etc.) which take a long time to actually kill enemies. If you are planning on bringing this weapon into a mission where individual enemies take more than ~1s of direct fire to kill, use full status with Secondary Encumber

Alterations

Remove [Lethal Torrent], replace with a primed bane: ~10% DPS gain, better ammo efficiency.