I'm aware of this. Listen if you don't want to try it, then don't. I went through every option before I figured this out. I thought it was tmau, candida, sibo, secondary tmau, a undiagnosed metabolic condition, internal rectal prolapse... I searched everywhere for answers and eventually found my answer on my own.
I'm posting this for people who are looking for an option. Not everyone has a metabolic condition, i would say that most people with FBO or similar, the problem lies solely within their digestion - or lack of that is. The worst is thinking you have tmau or something similar and don't. I was on a low choline diet for about 6 months and it was only exasperating my symptoms.
Strict low fodmap diet, betain hcl + super enzymes generously with every meal. That's my answer - it worked wonders for me and I went through years of hell before I stumbled on this.
The best part of this routine is that it only takes about a week or less before you see noticeable improvements. If it doesn't work then go back to doing whatever else you were doing.