Funny how wider than 8'-6" beam is suddenly acceptable...somewhere behind the scenes, Bill Roberts is probably saying something like "Welcome to the party...I have been trying to tell you this for the last 40 years"...
Well Bill Roberts should probably get that chip off his shoulder. The only reason that its "suddenly become acceptable" is because the dealer in North America is offering a turn-key tilt trailer that literally adds 30 seconds to setup and breakdown time over your traditional-width cats.
The extra width is also needed for the curved boards since the lift forces on the curved boards decrease righting moment via the leward board.