In my experience, without kern.geom.debugflags=16, the MBR will not be
written to the memstick, leaving you with what would effectively be a
coaster in the not-so-distant past.
The problem is that this bad suggestion is everywhere in the Internet.
And users use it always even when it not needed. I think it is bad idea
add it in the our official documentation.
When you doing all in the right way using debugflags=16 is not needed.
And it is really dangerous when you doing something what you do not know