Thanks Ttown! Looking forward to them.
Suspenders are underwear and not meant to be seen, at least not really. Every pair of bespoke trousers I own are suspenders-only. They are all high-rise and a belt would be wrong, both visually and practically, and I dislike side-adjuster tabs. If you wear suspenders correctly, at some point you realize that you haven't hitched up your trousers in a while, unlike when wearing a belt.
It has nothing to do with formality of an event and everything to do with how I want my trousers to look.