Looking for feeding options for four peacefully.

To start I have always fed my cats meals twice a day, getting wet and dry food. They are all domestic short hair. My first has stress issues so he’s on a prescription C/D stress diet of wet and dry. He’s always gotten his own food bowl twice a day. He’s perfect weight of 10 pounds. My second cat is now 10 and she needs to start on a senior diet. She is 11 pounds. My third cat Maisie throws up if she eats too fast. She is only 7.5 pounds. Even with a slow feed bowl she still eats too fast so I have to leave some dry food out for her to eat throughout the day or she just throws up everything she eats. Now the big problem is my fourth who even though is on a satiety wet and dry food diet getting the same proportions that all my other cats are getting he is now 20 pounds. I have tried feeding all the other cats while he is locked in a bathroom with his own food and he just won’t eat at All, which means he will just steal all the dry food that I need to leave out for Maisie.

At this point, I think the only solution would be to get a microchip or RFID feeder for all of them. Because Georgie, the big overweight bully will shove his head under other cats face just to seal their food.

Is there another solution I haven’t heard of for feeding four cats different food peacefully?

Are there pros and cons to certain microchip RFID feeders?

What do you all reccommend