I also have a problem with the big cover over the petrol tank as I have a "belly"..
I am presently investigating in the possibility of fitting a alternative tank.
The Kawasaki W850 tank can be modified to fit according to my oracle bike tech.
Obviously, this will void my warranty, but its debatable as there will be no alterations to the safety,structure or wiring of the bike and the original tank can be re fitted at any time..
Its nearly winter here so im going to try this out in December after my visit to the Canary Islands.