Not for me, maps, taskings, important area photos etc if you had a chest mounted camera surly all you'd see if arms meeting in the middle holding a gun?
For the above reasons and also personally there are times when I HAVE to have Comms on the field with me be it marshalling or playing. Don't need to defend the reasons but if I have to have it why not have it in a decent protected area and in such a way it's always accessible