HELP! Incessant Barking

Before I get into it, please don't suggest a trainer or behaviorist. I am (was, I no longer offer services) a canine behaviorist and I've done EVERYTHING reasonable and possible to stop the barking. I need some wild ideas that are feasible in our home. Do I have blinders on because it’s my personal situation?

TLDR: The barking is driving me mad and is super disruptive. I need wild hacks, suggestions on the best e-collars, thoughts on meds, and ideas for a fun loving, happy go lucky Standard Poodle. It has to work for our home set up and family dynamic which is probably the biggest struggle.

The Barker: 4 year old male Standard Poodle in our home since 12 weeks. Neutered at 2 years old. Very loved, generally well behaved. No medical issues. No boredom issues. Ethically bred.

If he could turn barking into a job, trust me, he would. I've done everything reasonable to control the barking including using bark stop devices and bark collars with sound, vibration, and as a last resort "shock" with zero results.
We put in a solid gate so he couldn't see out (the yard is surrounded by a solid 6 ft wall), didn't stop him outside. He goes straight to the gate and barks incessantly.

He barks at any chance someone could be near the front door, inside and out. He understands "Thank You" means to stop and walk away and additionally has good recall, but that doesn't work if someone rings the bell, knocks, or he hears voices at the front door.

He randomly barks throughout the day at nothing (humans can detect) and is difficult to redirect. He also barks at the sounds of daily life like a child "yelling" to get a parents attention, someone dropping a fork in the kitchen, hearing voices if someone is on speakerphone, and what appears to be complete silence to us while working.

If you've never been around a Standard Poodle, the bark is loud and deep.

My husband and I both work from home. Our home is 2 story and close to 4k square feet. We have children over 12 years old that are very involved with the dogs. We have a dog door. Someone is generally always home.
There is no situation where someone can be by his side all day for various reasons that don't require explanation here.
No we can't keep him by our side when working because of the barking and how it affects our ability to communicate with others.

Is it anxious barking?

Maybe, but it's also just become a habit of sorts. When we brought him home, I had another adult male standard, a rescue with a reactive history. He was a reactive dog and a frantic/anxious barker that was reformed with training and focus behavior therapy, but his behavior was never perfect because of his background. He has sadly passed, do think he laid the foundation for the barking I'm struggling with today.

Is he anxious?

More than I would prefer, but aside from the barking likely not something a typical pet owner would see as anxiety. He came home to us in the summer and temps made it impossible to begin properly socializing him until he was about 6 months old. I'd say he's cautious vs anxious. I successfully desensitized him to fireworks and fighter jets, so he's not that anxious.

Is he well trained?

He is well mannered for a pet but very spirited and excitable. His temperament can best be described as fun loving and enthusiastic. He knows what to do and what not to do but sometimes struggles on the follow through. An example would be immediately jumping to "hug" my one child whenever he comes home. I'd normally stop this behavior but it's particular to the one child he is bonded with and is very gentle, my child describes it as a hug. He matches energy with that child and their bond is so special that | let some little things slide that I might not otherwise.

Daily Barking

It's not practical for someone to be there every time he barks to redirect and reward. As I typed this, he was upstairs in bed with me, settled and quiet with the television on at a normal volume. Someone dropped silverware on the ceramic floor and he jumped off the bed and started barking. The barking is so loud he couldn't even hear me and I couldn't jump up fast enough because I had a laptop on me. Ideally we'd be able to show him the sound but for a long list of reasons that's not a reliable plan. If he barks at the door he's put in a sit stay and shown the person on the other side door, he's satisfied and quiet, but that a predictable and manageable situation.
We have multiple cameras installed outside. If he starts barking at the gate and no one is able to correct in person, we use the alarm and microphone on the camera. I sound the alarm for like 2 seconds to get his attention and then call him inside. It works, but not 100% and I'd rather find a way that doesn't include my neighbors or passerby hearing the siren and my voice.

Others dogs in the home do not behave this way. We have another Standard Poodle that is my Service Dog. She doesn't bark without purpose, but on an odd occasion may join him. They are both vocal during play. We also have a small dog that rarely barks.

My female standard (SD) has a serious personality which is the polar opposite of this male.
My next steps are considering an e-collar and maybe medication while we work through this. It's becoming a bigger issue by the day.

For anyone well-versed in the current options for e-collars, please weigh in. I would need one with a long range so it could be used from anywhere in our home. The e-collar would remain under my control. The goal would be him coming directly to me changing the behavior from frantic barking to "alerting" me.

I don't have a problem with medication especially as part of an overall training plan, but it's been years since I needed to medicate a dog so I'd love suggestions.

I'm honestly open to any suggestions as long as they are achievable in our family home. He has no risk of losing his home with us, he is very loved and safe, my nerves are just shot and I need to handle this for my sanity and to minimize disruptions in our home.

If you've made it this far, thank you! I tried to address as much as I could up front to avoid a thread of questions.