I bought an "x-tended" x-chock for my new Keystone Premier which also has the wide stance axles. It fit and worked great, although as others have noted, it's good for stabilization and is convenient when used with levelers, but not a replacement for standard chocks, especially when hitching/unhitching.
I found that I needed to use the x-chock "upside down", since the threaded rod comes out really far when the pads are extended all the way, and also it takes a long time to crank it out to the distance you need. So I'd like to figure out how to store it in a mostly extended position, yet still have room for the long rod - it won't fit in a standard sized bin if I try to store it that way.
2013 Keystone Bullet Premier 19FBPR