If you are putting a pot in it, then that means you are amplifying the guitar which pretty much negates the acoustic "resonance" anyway. I've personally put them on the top and/or put them into the "side" with no noticeable change in the acoustic only sound. Just my 2 cents. Good luck - T
A volume pot installed onto the top can not help the acoustical resonance of the top. Many CBG builders install them on the top side of the body by the neck. I like that spot also due to it's convenient to adjust the knobs there and out of the way.
Many high end acoustic guitars have all electronic controls mounted on the sides.