You can swap [Frostbite] for [Jolt] at any time, cascadia flare is better to kill stuff faster on lower levels but Secondary Encumber is usually better when dealing with tanky stuff on way higher levels since it stacks very well with [Galvanized Shot].

When fully stacked, [Galvanized Shot] is gonna give 120% damage per status proc, so with Secondary Encumber and a tanky target, it can get fast to 13 different status, that translates to 1560% damage just from stacking [Galvanized Shot] alone, also when fully stacked, having 4 status on the enemy is gonna be equivalent to Cascadia Flare.

[Hornet Strike] or Faction mod gives better average hit, burst dps and sustained dps than Using [Primed Target Cracker], so I went with [Hornet Strike] for comfort and with faction mod for the new murmur maps since ALL enemies are from the same faction, for fissure, survival/endurance, I would go [Hornet Strike] for convenience since there would be corrupted + another faction usually.

IMPORTANT:

Cascadia flare will give you WAY higher heat damage tick than if you use Secondary Encumber, both are viable but it all depends on what you want to aim the weapon for, a secondary a bit more for priming or for pure damage.