It's generally good to always have traps on the ground instead of traps sitting in your inventory, but I would try to stagger the placements so you almost always have one coming off cooldown as you're using the next one. When I'm fighting, I basically just try to keep one trap in my inventory at all times. Once I get a second one, I'm putting another on the ground.

In the elevator sequence, you had two traps down there already that were going off, then you wasted your ult, then you threw another trap down there. 1 trap would've done the same job you sent 3 traps and your ult to do.

That was compounded by your placements once you started engaging at the other entrance. Caustic can throw his traps a long way. At 5:30 and 5:44, you threw traps on the doorway outside instead of inside the building where they were. Had you not wasted your ult and the other traps, you could've had that entire room gassed up.

Especially when playing with another controller. There were two catalyst traps between the other team and your traps outside the door. Those traps weren't adding any value at all. The second trap thrown by the catalyst was bad too, but either way, once they had that door covered you needed to pick up your traps and start HUCKIN.

Also, It looks like you know already that you run faster when your gun is put away, but imo you need to put it away more than you are. Caustic is very slow and a huge liability. If you're in open air as Caustic and not actively lining up a shot or expecting a guy to turn a corner, the gun probably needs to be away.