Hiding things is suspicious, to an extent. But the point of hiding something is so that no-one finds it. If someone finds it, you didn't hide it very well.

Strapping a package to your chest and then going through airport security sounds criminally stupid or just criminal, but wearing a money belt while you travel sounds like a reasonable precaution against losing your wallet. Its all in how you look at it.

On the other hand, this kit isn't reserved especially for suit and tie occasions, how many people carry their EDC when they're swimming? You could wear a waterproofed version quite comfortably and discretely under your swimming trunks or perhaps even stitched to your swimming trunks. Or you could carry it while jogging where the light weight and low profile would keep it from interfering with your running. In reality its just another way to carry the ubiquitous Altoids tin kit.