Well.. I did it, not sure how much of a difference it will make but I'm sure it's not going to bother me to wonder if I could get a better picture..
The reason I won't know if it made a difference, I just got this TV used. While waiting for the UPS guy to show up with my new DMD, I decided to do it. It was a LOT easier than cutting all the sections for my CRT RPTV, that's for sure.. and afterwards, you couldn't see anything but the mirror, the lens and the IR pickup.. It was complete darkness in there. Mits left a flat plastic surface that could almost be construed as a greyish tint inside. I am hoping for a nice rich color and true black experience!