I was reading this information on a Credible website That if you use a Keyboard cover like the one's that Moshi sells "Clearguard"on your Retina Macbook Keyboard it actually blocks the heat coming out from just around the corners of the keys and there by will make your Retina Macbook more warmer. Also it said that, if you are using this keyboard especially on a 13 Inch rMBP it will also reduce the sound output as a lot of sound comes just beneath from where the keyboard on the rMBP is ! is this True ? is this Correct ?