If feng shui had any practical utility, then it would be applied everywhere. But mostly it is used as a means of psychological complacency. If a person believes that some actions will bring him good luck/are simply right, then he receives a charge of positive emotions, regardless of whether he is right in his belief or not. Thus, feng shui only works if the person himself is sure that it works. In a way, this is the paradox of self-fulfilling expectations.
I think the real understanding is not as simple as you think. Fengshui is a belief system from ancient Chinese heritage, and it is not a means of psychological gratification. however, the cultural practices applied are passed down from generation to generation.
Fengshui itself does not mean that one will get success after practicing it especially in this case gambling, of course as you said, if fengshui has practical uses, then it will be applied everywhere. it will never work.
I think the meaning of fengshui has strayed far from the original source. As far as I'm concerned,
fengshui is the practice of harmonizing energy to achieve harmony and I'm not sure if fengsui can be linked to one's luck when gambling.
If we try to formalize the words that I have underlined, I am afraid that everyone will come to an individual result and it will be philosophical and not practical. This is what I wrote about - those people who use feng shui see it as a specific meaning for themselves and it works for them. If you try to transfer it to another person who has different views, then most likely he will say that Feng Shui does not work.