That's incorrect. A friend and I have had several regrinds done by Oregon. They reground a factory hyd roller for him and got it to 108. Still had plenty of meat left. Remember, a good cam grinder can put that lobe anywhere in relation to the cam core he wants.
Let me clarify somewhat. There are TWO different cores for the Magnum engine. Now I forget which is which. There's the 318 and 360 core. One has a 109 factotry LSA and the other a 113. But still, it was the 113 that they were able to get to 108, so there's room to move them if you find a good grinder.