I had the big ass IMS tank on my KLR. I never mounted the front bracing which allowed the tank to flex somewhat on contact. If I had the front of the tank braced against the radiator frame, it would have damaged it. Several off road biffs later, no damage at all.
Looking forward to SteveRed's pictorial of the tank off and on the bike and how it will be plumbed to the main tank. Take lots of pics!!