So did some quick testing yesterday...planning on doing official test flight this weekend, but here's what I found out:
Like in real life, the main goal of the cable cutter is to spot the cable from hitting the blades. If you are going to hit cables, you need to make sure they hit your canopy and then the will be moved to either the top or lower cable cutter. So In the quick test I did I hit the cables directly on making sure my rotor blade was just a bit higher - no damage. If I hit it too low and my blade contacted - normally lost the rotors and didn't make it.
More testing will be done this weekend. But essentially, avoid flying into wires...but if you do make sure the rotor blades are above them.