Yes feel free to post in any other forum as well. I hear your concern and frustration and believe me I would totally have loved to be few inches taller as a 6ft i wish i was 6'4 in my years practicing basketball. Unfortunately that didn't happen and since I was short so i had to play faster and smarter.
Regarding your question i agree with you. However some research has been made by the Broad Institute. According to the Institute "Over a century ago, scientists first proposed that height is a complex trait — one influenced by environmental factors and multiple genes"
Now to your question of "increasing height after growth plate fusion" you really have to monitor this condition with a specialist since there may be surgery involved and post recovery may get affected as well.
When comes to physical training there is research and you can try for yourself how exercising using strength training or Yoga can improve your posture and physiology meaning that if you are 5'9 after strength training you may stand taller to 5;10-5'11 but not more and this takes time believe me!
This area of research lacks interest since there has to be funding or also a strong need and although you may find some people interested still there isn't sufficient support to start funding programs around the coutnry.
As you know height is affected by several factors like DNA, hormones or nutrition so hormonal activity it is extremely important.
HGH travels through the blood and stimulates the liver to produce a protein called insulin-like growth factor #1(IGF-1). IGF-1 helps the cartilage cells located at the ends of long bones called the growth plates to multiply, which is where bone growth occurs. Human Growth Hormone has a major role in height increase but i would strongly recommend to not take it unless your doctor approves it.
Talk to your doctor and see how you can incorporate strength training into your routine and see if you can stand taller and incorporate an inch or two if your muscles are stronger and your spine is straighter.
Stretch every day: Lower back stretch: From a standing position raise your arms overhead and lean backwards gently hold that position for at least thirty seconds.
Raise opposite arm and leg with 5 lbs-10lbs dumbbell. Strength training will help your muscles stay strong and tight helping your spine's alignment
Practice core strength-balance exercises require an active use of your core forcing muscles to stabilize and stand straighter
You may be looking for 1-2 inches taller not more.
Follow a healthy nutrition especially calcium, vitamin D and protein. Keep stress and anxiety to the minimum since stress might tighten up your muscles and make you look shorter...
I hope this helps!