I use the AF-ON button on the back of my D3 for focusing exclusively and I half press the shutter for AE locking. I newer realized that the AF-ON button is deactivated when the shutter is half pressed so I cant refocus in that situation and I would have to loose the AE lock in order to refocus.
With all my newer Nikons I can refocus when the shutter is half pressed. Is there a menu feature which would allow me to refocus when then shutter is half pressed? I dont seem to have enough thumbs to push the AF-ON and AE-L button on the back of the camera at the same time when recomposing.