There was a lot of talk about this on the ZRX forum, rumours abounded of people on Ulysees having a peg break while standing up on it (!!!!!!). This isn't helped by the fact that you had to slightly nibble the webbing that provides all the strength (the gusset) to make it fit.
In the end, it was determined that the pegs are likely NOT going to break from just standing on them, and any that did break on the Adventure bikes had been shock loaded on rough surfaces and/or dropped onto the pegs without someone realizing they were taking damage.
I put them on my ZRX, and the thought of a peg breaking while standing up for a few minutes to stretch your legs (ain't gonna happen on a ZX-14 unless you have LSL haha) was enough of a nagging thought at all times that I made sure to keep my feet tucked in at all times.
shudder.