I think you might be right.

Unless you can find someone to produce an expanding fitting to match the thread on the guard bolts, and the void inside the Renthals.

I agree, the OE hand guards are tougher than people give then credit for (just don't use them as a handle to lift your fully loaded bike up !!)

Rox make one of the best...

Ive just fitted some 15 mm risers off ebay and lift it just nice. My main problem Im thinking is the bend of standard bars, where I seem to like them I feel as if my wrists are turned inwards and my elbows go out. My prefered bar has always been Renthal 613s so may go with them when I get some funds.
If some of you feel the rubber inserts in the top yoke cause twisting, you may be able to go with the same things I used on my older 4MY 660 from Kedo in Germany... plastic inserts that do away with twisting bars

Definately