Well, I'm not sure I've understood the actual uncomfortability of the game but as far as this problem is concerning just the 1st and the last page you can try to turn the 1st page in contact under the last. The very weight of the book will take care of the bending and since 1st page is just narrative you will not need it after reading it.
Play your games turning the 1st/last page pack according to weighter part of the book.
Not a solution but a way to play...
Thanks for the reply. Agreed, and what you suggest is what I had resorted to doing. However, I'm curious if there is a way to get this type of book cover to lay flat anyways. The amount of warping in the covers is quite extensive, making even the book pages slightly warped from storage.