No; the knurling actually bites into the composite surface of the blade, to increase resistance to movement. The knurling was one of IVO's attempts to stop blade movement; the initial design had smooth faces on the hub plates.This may have some bearing on the issue......something interesting I found when bending T3 aluminum in a pan break.....the traditional method of setback of the clamp did not produce the proper bend radius because the hard material would lift and bridge to the clamp and the radius would be sharp........
so perhaps the stiffer IVO prop when torqued .....the fibers are bridging (or warping?) between the bolts and not contacting as well as a wood prop....obviously there is a difference. Just an idea.
The critical difference between the IVO and traditional props is that the IVO doesn't use drive lugs mated to close tolerance holes in the back of the blade.
edit: The IVO isn't stiffer; it's quite a bit more flexible than carbon or even wood props.