I don't have an answer to your question, but I too have tree roots that have grown big enough to scalp.
So, knowing they're only going to get bigger, I removed enough of the root tops to no longer be a problem.
I took a pick ax and used the hoe part of it as a planer of sorts to slice off the worst of the top of the roots. Doing it this way was a lot easier than to use a saw, chisel and hammer. That approach works of course, but it's brutal on my back and knees.
The roots I planed with the pickax appear to be healing nicely and I don't to worry about damage to my blades or whatever else could be damaged.