[malky]

The issue with that is in shortening the fork tubes to fit in a way to allow the normal fitting of handlebars. Hitchcock's solution leaves a lot to be desired, in terms of esthetics.

I was looking at strengthening the top yoke and tig welding modified/shortened risers in place.

[heloego]

   IMHO the oil filter location is basically OK. Anyone who has had to open up a spin-on filter knows that metal housing is tough as hell! At least on all the ones I've had to open and inspect. They all required a tough as nails special cutter (expensive) to get them open.
   Any rock thrown by the wheel shouldn't be an issue. It's the ones NOT small enough to be thrown by the wheel but slam into the front that one should worry about  . THey'll do a lot more than damage the spin on. 

[Narada]

Could the oil filter location have been chosen to help in cooling the oil?

[Ice]

 It's nice to see pics of the test mule in public. They confirm that the P twin is indeed real and authenticate the previous spy photos of it.  They also confirm  media reports from as far back as January 2011 of it's development.

 The longing is now intensified by a notch or two on the want factor scale.

 Looking at the all the available photo's I wonder if the oil filter location was dictated rather than chosen due to lack of space elsewhere to put it.