My problem with cameras is
finding one that is not too expensive and doesn;t mount on the helmet
The problem with the helmet is that I ride on a lot of paths and often feel the top of my helmet brushing passing branches and canal bridges
This even happens on some roads
Worst case was when a part of a branch managed to slip through one of the holes in the helmet and as I rode on it janked my head violently back
Luckily no car was passing me at that exact moment and then the angles changed and the branch slipped out of the helmet
How I stayed on my bike is a mystery
hence my aversion to something sticking up a few inches (

) further
But I presume one on the handlebars for suffer from vibration?