I don't know about this. Yes, you need to be careful with brand new tires, but people go off the deep end IMHO.
When you have brand new tires, you need to be light with throttle input for a few miles when leaned over. It's that simple. The "50-100 miles" is complete ******** in my experience. I have my tires broken in after about 5-10 miles. I have never sanded them, nor have had I had any problems. And I go through a lot of tires.
This is what I do: After mounting the new tires, while traveling down the road I weave back and forth (within a single lane). The weaves are small at first, and slowly progress to bigger ones and greater lean angles. The goal is to scrub, or roughen the tire's surface in a progressive fashion from the center to the outside. That's it. Most likely, they are fully broken in within a mile or two.
All the problems where people have crashed with new tires that I have personally heard of have been due to moderate to aggressive throttle input while leaned over within a mile or two of tire installation.
Don't fret over this too much. Don't be an ***** either.