Try this idea,

The extended wingtips provides a higher aspect wing ratio. Higher
efficiency.  Lancair says the gross weight doesn't change but then  you are
on your own without the company support for this over gross trip anyway.
Perhaps this will reduce your fuel consumption and allow you that extra
margin of lift to fly at altitude and inprove fuel efficiency???? Just make
sure they don't fall off or get scraped on the ground like the voyager did
on its initial takeoff.  In your case that could be disasterous.

Bob Smiley
N94RJ