It may be time for a completely chaotic reset.
You write that as soon as you go to get the treats, the screaming starts again. Have you ever heard of Ivan Pavlov's dogs? Pavlov rang a bell every time before feeding a dog and the dog started salivating when hearing the bell, even if no food was provided. You do the same, but instead of ringing a bell, you stand up and walk to where the treats are stored. Your standing up is already a reward for your cat. That means the can is actually reinforcing the screaming before you can reinforce silence.
I propose breaking the connection between standing up to get treats and actually feeding treats. You should get up and get some treats at completely random times during the day, but never feed any cat any treat. Just get a treat, go back to what you were doing while holding the treat for a while, then get up again and put the treat back. No matter what your cats do, they never get the treat. This will take several days and many repititions each day to break the mental connection between you getting up and the cats getting treats.
Apart from that, the amount of destructive energy of your vocal cat worries me somewhat. Could he be bored out of his mind? If the only entertainment he gets is getting on your nerves until you finally react, this is also a positive reinforcement from your cats point of view.
We see the same thing in neglected children. If the only time they get any attention from their parents is when they get scolded for whatever they did wrong, they will deliberately do wrong only to get attention, even if it's negative attention. That is not to say that you neglect your cat, but the mechanism is similar.
I would try entertaining your cat more. For example, you could feed them by hiding the food all over the place instead of presenting it all in a bowl. Putting up random cardboard boxes with some cat-sized holes makes a great cat adventure playground (that can also involve hidden food). You can redirect the destructive energy by making DIY food dispenser toys like this example. There are mechanical ball toys that move around on their own. A toy on a fishingrod-like stick works great.
Usually cats are less active than dogs, so you should be able to exhaust him this way. Try it out and see if the screaming improves.
And lastly, if you manage even the slightest improvement, I would introdice negative reinforcement (aka punishment), but never in a physical way. You must never hurt your cats or they lose trust in you, which can take years to repair.
Instead, I would shut the cat out of the room as soon as it starts screaming. I know you write that it's screaming constantly right now, so this method cannot work right now. Your cat needs to calm down enough for you to reward it and as soon as it starts vocalizing again, you move it out of the room and shut the door.
To get anywhere in the training, I suggest talking with your vet about admionistering a mild, slow acting tranquilizer. There are special products for cats that take 5 - 10 days to start taking effect and are designed for stressful events like moving houses or fireworks. I think it's worth a try in your case.