I agree with bringing the wires through the bottom as well. However, I totally disagree about going through the back of a wall or board unless it's been laid out that way for EASY access. I can't tell you how many jobs I have been through where someone has done that and left this tiny ass pull string in a jammed hole behind a block thats been locked down cause the previous tech went through the center of the bracket. Yeah, it looks nice after the install...and them anything added later looks like dog crap and takes twice the time and agrevation. I line ring routes and or panduit if need be for a proper cable route so that later when you go to add cables it's not a pain and it continues to look good.

Just my 2 cents.