During my last troop (with borrowed armour), I found that my cummerbund started to slip down after about and hour of trooping. I kept thinking about that rather than concentrating totally on the troop. My pouches also need a larger area of tethering rather than just the upper hinge too, especially as I was carrying most of the troops wallets and keys in them!
Here are my solutions to my two problems.
I bought a pack of four black military shirt stays to act like suspenders. They have clips already attached, they have adjustment clips, and are shorter then suspenders. One would have been enough on each side, but I wanted there to be room for adjustment, so I neatly joined two together using a decorative zig-zag stitch. The zig-zag keeps the edges from fraying and allows a bit of stretch in the joint. I made small button holes directly on the cummerbund for the stays to attach.
When I put on the cummerbund, I just undo the main Velcro on the back, leaving the under-strap still attached to the Velcro, and the stays in place, and climb into it.