Apply conditionals + switch to AUTO mode - fully stacked dmg x the 20 times multiplier from last evolution - ludicrous DPS.

Evolutions:
-40% recoil
On headhost: 30% reload speed
+50% headshot damage
50% chance to deal 2000% damage on non-critical hits

I've run this gun as my main for the last two weeks, and I say this is the most optimal setup (mods&evolutions).
For cambion swap elemental mods to Corrosive - did solo Steel path there, easily ...

Further improvements might be, to put another two forma for 90% elemental mods, for most raw dmg, but I like the additional status chance, one heat proc will kill w/e is left alive.
If you get a Riven mod, depending on stats you might want replace either Primed Fulmination (if extra AOE not necessary) or Hornet Strike*.
^: if you want to keep swapping mod configs - bane mods provide twice or thrice (primed variant) the dmg of [Hornet Strike], but really, if you are not doing any ridiculous farming strats or going against 300+ enemies, I find it tedious to swap per faction.
What is nice for [Hornet Strike] it gives the boost for the intial unstacked kills, which is actually quite nice little perk.

I am farming out the Secondary Deadhead arcanes, I think it would be better than Secondary Merciless, because when maxed it gives the extra 50% recoil reduction, and buff lasts longer, and it is not an issue to get 3 HS kills with this gun, you get used to aiming in their Heads general direction anyway ...

This is the 3 forma build, already enough for all content:
https://overframe.gg/build/315875/laetum/3forma-viral-enough-to-wreck-steel-path/

p.s. I ran this gun as crit variation with my fully formated Kavat, crits galore, pretty fun also.