I don't think you can fire 3 times without Psycho-temporal Contraction and Adrenaline shot which gives you 4 turns of fatigue after it ends so it's not something you can use all the time.
You can one-shot everything with a proper elemental bolt with a crossbow on dominating, with laser pistols it easy to stack crit to 100% with insane multiplier and good damage from intelligence, and even if they don't kill in one shot they will in two. 9mm Chimera with AA scope and Muzzle can mow down half the map if you get lucky.
They are definitely not in the same tier as other weapons, and I would even argue that some weapons are in the same tier as PSI since Expedition.
They really didn't receive any meaningful buff with expansion, Psycho-temporal Contraction does not give them more shots, they didn't receive OP belt like Bolt Quiver, specialization points don't really give them a meaningful damage boost they already one-shot everything, they don't really benefit from Versatility specialization and higher stats like light weapons, etc. They even have a strength requirement.
Sniper/Shotgun does sound nice, I am going to try that. Maybe PSI/Sniper for some shenanigans with Thermodynamic Destabilization. I know it can work, I just think it was left really far behind and need a serious buff.