I didn't have a lot of play with my case but I still did this mod anyways to solidify the phone in place. All I could find around the house (it's 12AM here) was
moleskin which is basically the same concept as the felt except for its pinkish color. I followed your "
template" in post 1 and it worked out great and even though I used the (pinkisk) moleskin. With the phone inside of the case and together I cannot see the moleskin at all and it functions great.