i actually have the components to build a 600 rmk turbo. It was on a 2008 and it was big fun until my motor went kaboom. I am not mechanically able to keep one of these on the snow so it sits in a box.
I would think the biggest stumbling block for most is the reasoning of why to start with a small motor when you could start with a big motor and build more power. Turbo kit is the same price. Off boost torque is considerably more with the bigger twin.
However, I would think wth how responsive the smaller twins are the little boosted motors would be a lot of fun. One of the funniest machines I ever built was a older 500SS ported and bored to a 662. Was right there with any 800, but the throttle response was considerably better.
Actually the 600 is lighter then the 800 plus that's the same bottom end as a m7 and those were great motors. Good enough for cutler to make a dragon cat 1000 billet top end for it so I'm sure it will handle the power. I used to own a m6 and studied every way possible to get the most power out of that engine.