FWIW
I generally only punch to the chest in chi sau (at least in the first instance)
because
a) It allows me to hit harder and stops me from flicking or pulling my punches or over extending to hit (which are bad habits which come from being a head hunter and which most wc people IME have from indulging in too much long range 'tag' chi sau)
b) It conditions my partner to take strikes without busting his face up (and vice versa)
c) A good body shot can be just as effective as a head shot and easier to get given that most people tend to protect their head more than their body.
Moreover a body shot can then be used to set up the head shot when he drops his hands to try and defend it...also...the head is more mobile than the torso and someone with good head movement in all directions can be hard to hit. It also leaves you more vulnerable to being taken down.
'In the woods there is always a sound...In the city aways a reflection.'
'What about the desert?'
'You dont want to go into the desert'
- Spartan