Depends greatly on the limb design and taper rate. I start out about 2" from fade, but figure after layout and shaping, when I blend the line of limb layout into the riser area, it is close to fade.
What I dislike is a bow that has a pronounced hingey looking area right off the fade. So I use a power lam on just about every bow to help the riser fade spread the weight out some.
The risk I suppose would be working the bow limb more at fade than anywhere else. Which might eventually cause it to fail....
YMMV