High Voltage needs more juice
I get the idea behind the ability: to get the full damage, you need at least two tendrils to hit. But it does so much less damage now on a single hit for an attack that's supposed to be a focused blast counterpart to the regular AoE (2/3's in fact) and already frequently misfires by targeting unhittable targets, it's in a really rough place.
Even arguing it as a single-target Colossus nuker is harder because the beam end up still the go-to for most of those fights. And even on that build you have the standard AoE AND the hop burst so it cranks out more damage.
Ultimately High Voltage currently feels like a worse option than going in with not transmod at all. The lower cooldown and range do not counteract the lower DPS.