Having flown Yaks, both of the Wild Hare Sukhois, and two smaller Suks some years back, my experience has been that the farther out the prop is from the cowl the better the power response. Think about how much propeller extends beyond the face of the cowl and contemplate how much "work" is being efficiently performed at the area covered by that big open bucket. Why do people think round cowl planes fly so slow?

I set mine up close to an inch out. My big Yak is a little further than that. If it looks good the distance won't hurt anything. Your choice so don't let what others have make your decision for you.