Hi HGP61, yep understand what you mean by the centre to centre measurements, measuring the width of the tyres is not a very accurate way to go about it.
I added that last image of a Kawasaki Patent that I found in an article by Bennetts back in January 2021. I thought you might find it interesting considering the tilting mechanism has been moved from the top of the bike to in between the wheels, in this design they use existing suspension of a bike, although the forks appear a lot closer together.