With a shirt button, the object is strictly to keep the shirt closed. The button, inserted into the hole and twisted, does this. There is no gravity involved. A brace button on the other hand serves only as a tying point for the thread and to keep the brace strap from slipping off. But the thread of the brace button becomes like a tiny girder to hold the pants up against the force of gravity, the force of up-and-down movement and the force of an often large ass. I know this because I majored in buttons in school.
The only thing I would add here is that there have been times when my collar button and the waist button on my chinos would protest that if we're talking about stress, they deserve to be classed with the brace buttons.
Speaking of brace buttons, here's something you might consider. Or make fun of. Your choice.
You make it sound like either-or. In this kind of situation, I generally prefer both. :icon_smile_big:
It's sometimes discussed here the anguish of putting the buttons inside or outside. What to do, o what to do. You could do both. Front inside, rear outside.
Aha! See, you think as I do. Now, the other place I saw the inside/outside suggestion, the guy said it should be the back ones that are inside, so they don't catch on stuff. (Actually, what he worried about was marring the leather seats on his Rolls: https://www.bownsbespoke.com/albertthurston.htm
.) But he's a snob and a twit, whereas you are a charmingly abrasive eccentric, possessed of a genuinely free-thinking and innovative spirit. Reason enough to consider your suggestion. That plus the fact that you've actually tried it. (And you haven't had those back buttons snag on stuff?)
The other thing I've wondered about is whether buttons in front on the outside makes more sense when you're worried about waistband roll due to the geometry and forces set up by the presence of an oversized gut. With the buttons inside, waistband creasing and roll seem more likely. With this I have some, ahem, personal experience.